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Could it be right to pass, rather than double, an opposing opening bid with 14 hcps, and three cards in each unbid suit headed by an honor?
"Pass" is what an expert (Frank Stewart) advocates with the following hand, at rubber, at favorable vulnerability, in response to a one diamond opening bid by RHO.

Spades
QT4

Hearts
KQ3

Diamonds
Q64

Clubs
KQ62

Specifically, Stewart wrote, "I would be ashamed to table a hand like that, after forcing my partner to bid." I (the OP) am a conservative bidder (perhaps overly so), but "Pass" seems overcautious even to me. Especially when non vulnerable vs. vulnerable.
The worst case for partner is a "Yarborough" and a 3-3-4-3 distribution (with the four in opponents" diamonds). But as a practical matter, the worst likely scenario is that partner will have only Jxxx in his "best" suit. This would play relatively well opposite KQxx, KQx, or QTx in the three unbid suits. A three pointer, with all three non-diamond jacks, could play very well. I don't see the shame in that, even for a forced bid.
I would rather double with the above hand than Stewart's other offerings, hand one, which had three cards but no honors (or even a T, 9, or 8) in the spade suit, or hand two, which had a "side" suit with only two cards (clubs).
Is a hand that meets the description in the title a clear double? Or are there 14 hcp balanced hands (regarding both cards and honors) that should be passed?

100% pass.  "Not even think" pass.  If you're worried about "what happens if", this is the hand to worry about it.  No, you're not likely to go 800, but you are likely to go minus on a "nobody can make anything" hand.  At rubber, that will cost you tiny bits that will add up over the year.  At matchpoints, -50 when you could have been +100 is almost as big a loss as -50 when you could have been +400.
All my arguments from the previous hands apply here:

⋄Qxx is not only wasted values, it's valuable on defence.
If they have a fit, partner will do something ("short hand acts"), and you will be happy to support whatever she does.  If they don't have a fit, you're losing 3 diamond tricks, either straight up or A,K,ruff.
It's more likely that opener is balanced than if he opened 1 of a major.  Therefore, it's more likely that there is no fit at all (which you want to defend).
It's now screamingly clear that this week's course is "if you double 'because I have 13 points', stop."
specifically on this 14, look at which finesses are (potentially) on.  To me, it looks like just the ♠J.  That means any card LHO has is working to pick off your cards.  On defence, the KQx is likely two tricks.  On offence it could not be, if that's their fit and partner is short.

All of Forget...'s arguments on other of your questions also apply, in spades:

downvalue 4333s.
downvalue aceless hands.  They're better on defence anyway.
you have a partner.

If it goes 1⋄-p-p to partner, she will likely have the hand that knows what to do.  If it goes 1⋄-p-2⋄ (whether the opponents play that as "single raise" or as "limit or better"/"GF"), partner definitely will know what to do (at least if she adheres to "short hand acts" at all).  If it goes 1⋄-p-1NT, this might be fun.
Alternatively, if it goes 1⋄-X-2NT/3⋄ (whichever is limit raise), partner has nothing and declarer can see the entire hand (although he might play for partner to be ⋄Qxx).  Same for 1⋄-X-1♥-p; 2♥-p-4♥, with the benefit that trumps split better than they hoped.  Sure, if you pass, the same auction happens, but now maybe there's a misguess.
On the off chance that it goes 1⋄-X-XX, pull out your wallet.  I know, paranoid, but again, if it happens, the opponents know exactly what to do.
I'm more aggressive than Joe; with perfect shape, I'll double on a good 10 or less with no wasted values.  My partners know to double-check with a good hand.  I'll balance with even less and perfect shape, especially into 1m-1M; 2M-p.  But flat hands are a danger when they've opened, no matter how many eyes are looking at you.
Now, with my regular partner, I will act with this hand.  Because I'm playing something weird.  But:

I will make the same call with Kxxx QTxx x QJxx, or weaker at favourable.  The wide-ranging, aggressive nature of the call provides some safety.
I won't make the same call with most 15s, so partner won't go nuts.
That call is 1NT, not double, which takes away the 1♥ and 1♠ responses.
We are very prepared for the penalty "redouble" (actually double), and our rescue system is built to expect it.  We are much more likely to reach a fit than the regular takeout doublers (albeit at the 2 level).
There's a 2⋄ call in the system saying "bid your better major".  Now this time, I don't have a 4cM, but partner has that option with many hands that would have to "guess" over 1⋄-X-p.
I will take 100% of the blame if, even so, it was wrong to act.  And it will be, sometime, sure as apples is apples.

Actually, these articles took place over three months (June-August 2019) of back issues. My "series" of questions was a result of reading "June, July, and August" on different days. It would have been a lot more coherent if it had been concentrated over one week. Also, I'm astounded that the same call can be made with "9" on one distribution, and don't act with "14" on another. I had been using a narrower range;":Never below 11, and (almost) always on 14 hcps. That is a three point range instead of a 6 point range.

Interesting.  Brilliant of you to spot a pattern, then, if he wasn't putting it in place.  That pattern is Bergen's "Points Schmoints.  Shape rules." (or my summary of others' answers, "short hand acts".  HCP work very well for "relative strength", which is a great guide to "how high" in power auctions.  "Fit" and "losers in their fit" are 100% more important in competitive auctions/partscore fights.  Which is what takeout doubles lead to, more often than not.

I've seen others say that they would "double" with 10 hpcs with a 4-4-4-1 distribution, e.g.  with Kxxx Axxx x QJxx,. Does that mean that one could do so with  will Kxxxx Qxxx void QJxx? (8 hcps and 5-4-4-0 distribution)? I use algorithms to create grids like: double with  8 hpcs void in the opponents' suit, 10 hcps with a singleton, 12 hcps with a doubleton. In theory, 14 hpcs could accommodate a tripleton, but I would "throw out" many such hands on a case-by-case basis. At least if I subtracted an additional point for the bad distribution, turning 14 into "13."

Swap the black suits and I might, yeah.  Definitely bidding my 1NT for takeout with that partner.  Probably want something more though.  Overcalling 1S with the hand you gave (and potentially doubling next round if relevant.  Or not, if it feels like partner might pass.)  Please pay attention to the comments about "short hand acts" elsewhere to deal with the "3 cards in their suit" doubles - they're awful.  Note that every card you have in their suit is not only a potential other loser, but also a card you don't have available for "your fit".  Also know which HCPs are "waste paper".

The issue with this hand is that it isn't very interesting to play on offense.  Sure, if partner has a 5 or 6 card major suit, then it might play well in that suit at the 1 level; but unless P has 8+ points, or a very shapely hand, I don't know that we really want to get in the auction here.  This is a hand that plays just as well on defense, and you don't need to win as many tricks on defense.
Like the last hand, listen to the answer that talks about the law of total tricks; they opened a minor, so they maybe only have 3, maybe likely 4, and you only have 3 in the "higher" suits (the majors, here).  Even if partner has 5 in a major (possible but not terribly likely), you have 8, they maybe have a 7 or 8 card fit at most?  So 15 or 16 total tricks in the optimistic scenario, and 7 card fits are probably more likely - 14.  LOTT wise, 14 total tricks screams defense - it means maybe each side can make a 1 level contract.  Maybe. Wait a bit and find out; if P has a particularly unbalanced hand, P will step in and show you.
Typically, I'd want at least four cards in one major, and really would "prefer" it in both, over 1D in the direct seat.  I'd also be more likely to get involved with some shortness in opener's suit.  Both of those make it more likely you're in the 16 trick camp than the 14, and more interested in declaring.
Just to be clear, this is a little different than over 1H: there it's more tolerable to have 3 spades, if you have some other shapely attribute to your hand.  Here if you have 3 cards in both majors, and no real shape (3-3-3-4), doubling isn't of much use.  3-4-3-3 would be better, but it's still not that good of an idea.
You might want to look at some detailed write-ups of takeout doubles; Bridgewebs has a good one, for example that lays out all of the different options.  I suspect you can find others, particularly in book form, that go over this in more detail, but that page is a good start, both with examples and detailed rules to follow.
Most importantly, with 12-14 points, double with classic doubling shape, meaning something like 4-4-2-3 or 4-4-1-4; but pass with a balanced shape.  I'm a bit more aggressive than that, so I might bid with 4-3-2-4 for example, but probably wouldn't with 4-3-3-3.  Expect 15 or 16 if opener doubles with a more balanced hand (as that makes it more likely you have something on offense, and maybe can play 1NT).

With this hand, I like the "separation" described in the following. I have all four queens, and two out of four kings (two out of three if you assume that the opponents have K of diamonds. I have 6 out of 16 face cards, and give opener credit for four, something like 2 aces a king, and the jack of diamonds. That leaves something like A, A, K and 3 Js for the two partners, and average o three face cards apiece. If my partner has the worst of it, 3 Js, we're OK at the one or two level. If the "best" (the 2 As and a K), a possible game. Either way, partner knows where we stand.

But if I understand you correctly, one should seldom double with a 4-3-3-3 shape and less than 15-16 hcps, Is that what you are saying?

The point is, though, what about this hand says "I want to be declarer"?  That's the thing about takeout doubles: they're saying to partner "Heya, I think we should be declarer on this hand, pick a suit for us please".  3-3-3-4 14 points doesn't say that.  It says "I really don't care who plays this hand or in what suit".

If P has that A A K you talk about, then this will go 1d - p - p - X, right?  Or something else?  P will balance, and you will then be able to show that game.  And if P has a long suit, then P can bid it also.  But if P is also balanced, and has few points, and the bidding ends up  1d - p - 1nt - ppp, do you really mind all that much being on defense?

In your answer to my other question (hand one), you seemed to tell me to double rather than pass with the 3-2-5-3 shape, (with hearts being bid and my "three" spades being 532). I have trouble reconciling that answer with this one here.

3-2-5-3 is much more shapely than 3-3-3-4, though... It's okay to have a 3 card major, what's not okay is to have really no shape at all.

The difference between Kx in the opponent suit and Qxx in the opponent suit is about 0.7 total tricks, and that's before counting the higher likelihood of having more trumps in your own suit.  Your first duty in a competitive auction (after deciding that you have enough for the auction to be competitive) is to help partner count total tricks, because that's the most important factor in all competitive auctions.

This is a long comment, not an answer.
When you learned bridge 50 years ago (directly or indirectly), people thought of scores as follows:
+110 - "Great; we bid the contract we should have."
+200 or +100 - "Ooh we got lucky and the opponents overbid."
-100 - "Bad; we overbid."
-110 - "They had the cards; too bad."
Hence, the psychological evaluation of scores is +110 is better than any of +200, +100, and -110, and -100 is worse than all of those.
Needless to say, that is not how bridge scoring works.
Your reaction to +200 should be "Great; we passed when we should have." and your reaction to both +100 and -110 should be "Bad; we didn't bid when we could have done so for a better score."
You need to change your bidding rules accordingly to account for the fact that knowing total tricks is more important than knowing what you can make.
Actually, instead of changing any of your rules, I'm going to suggest you add another imperfect rule for a year or so: "Never let the opponents play in 2 of a known fit."  (That means, when the auction goes (1H)-P-(2H)-P, you alert partner's pass as "forcing unless I smell a rat".)  That rule is almost guaranteed to improve your matchpoint scores more than anything else you can do at this point.  Then go over your results, figure out when that rule was wrong (or the rule was right but you competed in the wrong strain), and try to figure out how you could have diagnosed as a partnership that the rule was wrong.
I think far more accurate than what you have is doubling with 13 hcp with 3 in their suit, 11 hcp with 2, 9 hcp with 1, and 7 hcp with a void (and 3 fewer in balancing seat).  Subtract 1 for an aceless hand, subtract 1 more for a Q or J in their suit, 0.5 point for each vulnerable partnership, and do some more partial hcp adjusting for finesses since RHO is stronger than LHO.

So those "14 hcps" hands weren't really so because of "stranded" honors in the opponents' suit? Makes sense. And I recommended "doubling" with the above hand based on "maximin" criteria, that is, the scattered queens and kings played relatively well opposite a "nightmare" partner hand of one or two Jxxx holdings.

The only time you should think "maximin" is if your opponents are hopelessly bad (which many opponents are!) and you're still trying to win rather than get practice for playing better opponents.  Otherwise make some attempt to integrate over the whole distribution.

Also, you're still thinking in terms of "What are my chances of getting -100?"  That's the wrong question, because -100 is a good score when the other possibility is -110 and a bad score when the other possibility is +50.

I'm a "rubber" player. I barely understand matchpoints. "Maxmin" means I won't lose too much money in one session.

At rubber, it also means you're leaving lots of money on the table without realizing it.  You can keep buying insurance, but when you do you should be aware that the insurance company makes money, which means you shouldn't buy insurance on losses you can afford to eat.  (I never play rubber, since I'm personally against gambling.)

@AlexanderWoo: re "I'm personally against gambling": "Bridge is a game of luck only as played by the justices of the Ontario Superior Court - in chambers" - Eric Murray in defense of the Regal t. Clair Bridge Club, Toronto.


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Could it be a bad idea to try to compete when the opponents have stopped at two of a minor
With both sides vulnerable at matchpoints, I held the following cards: ♠ 8653 ♡ J3 ♢ AK52 ♣ QJ4.
RHO opponent opened one club, I passed. LHO opponent bid one diamond, pass from partner. The next round was two clubs pass, two diamonds.
At this point, I hoped that partner would pass. Instead, she "balanced" with a double. I actually wanted to pass two diamonds doubled for penalties, but RHO opponent bid 2NT.
The two opponents made it, in part because they had AKQ of spades between them, and the 120 points they earned was a good score for them (and a poor score for us), relative to the 110s and 100s earned by others with their cards. If we had left them at 2 diamonds, they would have made it and scored only 90 (good for us, bad for them).
I would have been glad to stay out of the bidding because the apparent "misfit" limited the opponents' trick taking potential. Our bid pushed them into a better contract. Was this just an unfortunate result or was this really a good time to refrain from contesting the auction?

Partner made the reopening move - judging the sense of that really requires seeing that hand rather than your own.

@ForgetIwaseverhere: Partner had ♠ J742 ♡ Q7654 ♢ Q7 ♣ AT.

I'm pretty sure you misdefended.

@AlexanderWoo: The opponents had three top spade tricks (I led a spade), two top heart tricks, and several "long" club ticks. (The opposing bidders had six clubs and six diamonds, respectively.) We had three top diamond tricks and two top club tricks, and no "long" tricks (because of shorter suits).

@TomAu - Okay I see.

Yes - you compete less aggressively against 2 of a minor or 4 of a minor because those are generally poor scoring contracts.
Also, I play penalty doubles in that sequence.  If your partner had a takeout double of diamonds, they should've doubled 1D.  If they weren't willing to compete over 1D, they shouldn't be willing to compete over 2D.
Finally - you never know - RHO might have bid 2N without the double anyway.

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Was I right to pass my partner's two level overcall?
Both sides vulnerable at matchpoints, South opened one spade. West, my partner, overcalled with two clubs. North passed, and I was sitting East with ♠ J854 ♡ AT97 ♢ A843 ♣ 4.
I had no obvious bid, so I passed and so did South.
Partner was unhappy because we made five clubs (and could have made 3NT). But I was entitled to assume only a six card club suit and 12 HCPs in his hand. Had I bid one of my four card suits, we would have had (at best) a "Moysian" 4-3 fit in hearts, versus a 6-1 seven card fit in clubs. And I felt 2NT would have been a stretch.
partner had substantially more strength than expected: 15 HCPs, a singleton  diamond, and a semi-solid club sequence. He also had KQJ in hearts, which might be worth more in sequence than their nominal six points. With that, would he have done better to double and then overcall clubs even though his 3-3-1-6 distribution was "wrong"?
Put another way, did I underbid over the call he actually made (rather than the one he might have made)?

Nothing wrong with your Pass. Although you're maximum in HCP, with both your red aces working even opposite possible singletons in Partner's hand, your black cards strongly suggest a misfit for both sides.
The main argument against a Pass is that you know from your own Club holding that LHO is almost certainly not reopening. Balancing that: RHO could be a maximum pass due to an absence of available Spades. Partner's (presumed) major suit K and Q could easily be in RHO's hand instead, and you will be glad to have stayed out of this auction.
Partner however had clearly underbid. The traditional maximum for a simple overcall of a 1-level bid is 15 HCP. Partner has that, plus a solid six card Club suit. The correct sequence is to Double and then rebid Clubs.
This treatment is pretty much independent of system agreements, with the possible exception of pairs playing strong jump overcalls - but that is a very unusual treatment today, to the point of being virtually obsolete.

Partner had KQJ of hearts plus six clubs to the KQJT, as well as the K of spades. Both KQJ sequences were worth 7-8 points rather than six. Plus he had a singleton diamond.

Be precise Tom. A suit headed by KQJT is semi-solid (missing only one top honour) and not solid. You confuse matters immensely when you are loose with well- and long-recognized terminology. Also, don't put opinion on point count evaluation in comments where it can't be down-voted if regarded as inaccurate.

OK, changed reference O "semi-" solid club sequence in question. I also added "He also had KQJ in hearts, which might be worth more in sequence than their nominal six points." Thanks for your help.

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Are Moyesian fits more playable at matchpoints than rubber or IMP, bridge?
A 4-3 trump fit is known as a "Moyesian" fit after an expert who liked to play such hands, even with fewer trumps than the standard eight card fits.
Their main downside is that with six cards in the opponents' hands, one opponent would occasionally have a longer (five or six card) trump suit than the declarer. This would lead to control problems, and potentially to large sets.
In duplicate bridge, particularly matchpoints, the frequency of the wins is more important than the size of the wins. In my club, at least, players that bid good Moyesian fits (those with good high card control) tend to do well in the scoring. The boards on which they lose to long opposing suits don't hurt them much because the size of the losses don't matter as much as their rarity.
Would playing Moyesian fits generally be a better idea in duplicate, given the differences in scoring between rubber and duplicate bridge?

Differences in declarer/defender skill is crucial here.  Some partners I am much happier to put in Moysians than other partners.

@AlexanderWoo: A key skill for "Moyesian" play is ducking, rather than ruffing in hand so that the ruff of an opposing long suit eventually takes place in the short trump hand. A second key skill is having extra high card points in reserve when you are bidding with one less trump than normal.

@TomAu: More fundamental to successful play of a Moysian fit: Be a superb declarer, as Alphonse "Sonny" Moyse Jr. himself was. Generalizing that "play of difficult hands requires not ruffing in the long hand" would presuppose that difficult hands are now easier. Not true, as perhaps a cross-ruff is the correct line. Barry Crane, like Moyse, was a proponent of 4-card major openings; and likewise was unconcerned at ending up in the occasional 4-3 fit in consequence. Also, do you mean Match Points in the title instead of Duplicate? IMP play is also "duplicate".

I've can think of four common-ish scenarios for Moysian fits

I made a takeout double and partner bid my three-card suit.
I made a 4-card overcall and partner raised.  This can get you a good result a the 2-level and moreover, can push opponents to the three level if they want to compete, especially if they assume you and partner have an 8-card fit.  This is particularly valuable at matchpoints.
I responded to an opening bid with a 4-card major, and opener raised on three (not three small, but usually Qxx or better).  Many pairs swear by this style for matchpoints and has similar effects to #2.  However, when they try for game, 90% of the time they'll play in 3NT.
We explored for NT and found we lacked a stopper.  The main considerations: (a) strength in the suit, and (b) the 3-card holder should also have shortness in the partnership's weak suit.  If the 4-card holder is short in the weak suit, they will be "tapped", i.e. forced to ruff from the long hand or lose the trick, making it unlikely it's a good score in any form of scoring.

In my duplicate club, pairs that are willing to bid Moysian fits tend to do well, except when the six opposing trumps split 5-1 or 6-0, which doesn't happen too often.

An interesting question! However I think Moyesian is more the question of whether you want to play in NT or a suit, rather than a different strategy for rubber or duplicate.
When you can judge the right time to play one, you should score higher in both rubber and duplicate! - If a 3 card suit is accompanied by shortage in another suit for ruffs, then the higher-risk Moyesian often plays better than NT and scores a trick more. Although a 4333 shape usually plays better in NT.
It the question were altered to whether one should declare rather than defend with a Moyesian fit, I think it's still the case that when you can judge the right time to play one you'll do better at both rubber and duplicate. While duplicate is more of a part-score game, the Law of Total Tricks rarely justifies it and it's easy to bid on too high. Just think about how often you want to play a 4-4 fit as 3NT at duplicate, let alone a 4-3 fit.
Moyesians provide a good last chance saloon when NT looks suspect, which will often improve your scores, but aren't a substitute for a good 4-4 fit.


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Is card counting/watching a key skill for an expert Catan player?
In Catan, one can observe which cards opponents draw with their second settlement, and then observe what die rolls and trading do to their hands. Thus it is possible, though difficult, to follow opponents' hands.
In blackjack, the ability to "count the deck" represents the difference between being a winning and losing player. In bridge, players see 26 out of 52 cards, and through bidding and early play, can largely [reconstruct the two hands that they can't see.] There are probably no world class players that aren't reasonably good at this task.
Is the ability to reconstruct the opponents' hands of similar value in Catan for tournament players? Are there world class players or experts who weren't at least competent at this one aspect of the game?
Edit: My question was about the value of card counting in establishing one's rank in tournament play. The other question was about the mechanics of doing this in casual or "home" play. They have overlapping subject matter but their directions could not be more opposite. An answer that was suitable for one question could be wildly wrong for the other.

Does this answer your question? Counting cards in Catan?

No. See my edit.

The number of resources in the bank is not private information. There are 19 of each of the 5 resources. You can count the resources in the bank freely (though doing so frequently would be poor etiquette) which makes counting the cards fairly moot unless you want to do so without other players knowing your doing so.

Yes, card counting is a key skill for expert Catan players. First, most expert Catan players will be counting your cards and your opponents' as they pick them, with the only random variable being any possible development cards that you draw from the deck, or cards which you steal from another player when you role a seven. But as they will be counting your cards, this would immediately put you at a disadvantage if you are not counting theirs.
Once you can reconstruct an opponent's hand, you will know who you can trade with, what people need, and whether people are a threat to steal your spots for settlements and roads.
Although there are probably a very few world class players who are not that great at tracking cards, the vast majority of those who play competitively or in sanctioned tournaments are. And if they are not great in tracking cards, then they would have to be exceptional in another aspect of the game, like strategy, or be extremely lucky.

Card counting is not easy. That makes it unsuitable for casual or "home" players. There are other more important skills that will improve their game with less effort.
On the other hand, a tournament player will have an (almost) complete mastery of the game. That would include card counting. It might be one of the later skills acquired but for a serious player (one who plays for money or reputation), any extra edge helps.


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In Catan, if you roll a seven and move the robber, do you actually have to rob someone?
Rolling a seven forces you to move the robber from its current position, to another hex.
Are you allowed to move the robber to a hex (other than the desert) from which no one is producing resources? Your blockage of production becomes "trivial," and you have no one to rob.
Are there times where this might make sense? One might be from a "political" point of view, perhaps if you don't want to disturb the current balance of power? Or might it make sense to block a hex where you don't want someone to build a settlement, rather than actually having one already?

https://boardgames.stackexchange.com/search?q=%5Bcatan%5D+robber+steal this has extensive discussion on the specific question as well as other robber rules and strategies.

From the game rules

You must move the robber immediately to the number token of any other terrain hex or to the desert hex.

The keyword here being any. So yes, you can move it to tiles without anyone on it.
Although I've never done this myself, I suppose there could be an argument made to do doing this for a couple reasons. One of them, like you mentioned, could be to appease other players. Another could be to try and allow someone to even the playing field. If player A is very ahead and has longest road, but player B is tied for longest road, you could place the robber on a unsettled tile as to not steal from Player B and allow them to try and take longest road which might even out the score a little bit.
However, an important distinction here is that this does not mean you cannot steal if you place it on a tile that does have settlements or cities on it. If you place the robber on a tile with other players cities or settlement, you must steal from one of them.

Worth noting that in older editions, the rules did not allow you to move the robber to the desert; this was changed at some point; I believe starting in 4th edition.

Another good reason is to simply move it further away from your settlements, protecting your own ability to produce in subsequent turns.

While certainly jp's answer covers the rules, your question also asks about situations you might want to, aside from politics (both inside and outside the game. I can say we've changed the rules substantially in our house because I'm not a fan of sleeping on the couch. What can I say, Alberta girls are competitive.)
I immediately think that if you have 7 cards in your hand, and not a good way (or even possible way) to play them, then you're going to put yourself at 8 cards. I would still consider it worth the risk, because hopefully you can trade still, but it is certainly a valid reason to pass up on the card.
An unlikely but probably possible scenario would be if your settlements and cities happen to touch every possible tile on which you could place the tile to steal and you don't feel like blocking your own tiles. I haven't done the math to see if it's possible. I highly suspect in this scenario you would have much more territory (as it were) than your opponents and not in a great deal of danger of losing, but nonetheless I present it as a scenario.
While I have your attention, I should note that while you mentioned blocking a settlement, this is no more part of Catan than money in the middle is part of a Monopoly as previously covered on Stack Exchange (although admittedly that was nearly 8 years ago and things may have changed.)

I don't think the question implies a misreading of the rules. Even though the robber does not forbid placing a settlement, you might place the robber to discourage building a settlement (since it will have lower yield until the robber is moved). Doesn't seem like a very strong play to me, but the right scenario could exist.

@amalloy Conceivable, but the final paragraph is still noteworthy.

A situation where it may make sense to move the robber to a "neutral" location:

the next player has a knight card (or you strongly believe they do, and that they probably only have one)
that player's style is to hold on to a knight card as "insurance", and play it before their roll if the robber is "on them".
you are the player they'd obviously target, and looking for more of the resource they'd probably deny you

By moving the robber to a neutral location, that player won't play their knight, the robber will stay where it is, and you'll have a chance to get more of your desired resource - perhaps for several more rounds if the robber stays put.
Can backfire of course if they roll a 7 or play a knight card despite not being "under attack" from the robber...


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If you buy a house at "auction," can you put it on any property?
A housing auction occurs when there is a housing shortage, and people want to buy more houses than there are houses available. Then houses are auctioned to the highest bidder.
My question occurs under the following scenario: Suppose you have the orange and navy blue monopolies (one cheap and one expensive). Normally, I would pay $100 a house for the ones I wanted to put on the oranges, and $200 a house for the one I would put on the navy blues.
But let's say we were short on houses so there was an auction whereby I bought the house for $300. Can I put it on New York Avenue, or must I put it on Boardwalk or Park Place, since $300 is closer to $200?
All other things being equal, I would put the house on the higher valued blue properties. But suppose Boardwalk/Park Place already had three houses each. Then the difference between the third and fourth house is $300 for Boardwalk. The oranges have only two houses each. The difference between two and thre houses is $380 for New York Ave. Would it then make sense to put the extra house on the "cheaper" property?
(In my question, I meant "can" in two different senses. The first one is "Is this allowed under any reasonable interpretation of the rules?" The second is, does this make sense under the scenario I have outlined?)

The rules are unclear on the exact procedure:
. Building Shortages

... If there are a limited number of houses and hotels available and two or more players wish to buy more than the Bank has, the houses or hotels must be sold at auction to the highest bidder.

My interpretation is that everyone entering the auction must announce, on entry, which Colour Group they are bidding for; and upon winning an auction must place the acquired house on that Colour Group.
Further, if an auction is being held for more than one house it is likely best that the players agree to hold separate auctions for each one.  Some interesting game theoretic concepts might arise, in this circumstance, when an auction is being held for multiple houses at a single occurrence; and it would be a shame for these to not come to light.

Update
To be clear, my proposal is:

A house auction begins when players have stated intention to buy more houses than there are houses available.

To have stated such intent, each player has, per force announced the Colour Group for which they are buying a house; and must have the capability of making such purchase from cash on hand (House Rule: and by mortgaging additional properties) but not by selling houses back to the bank. An invalid entry comprises Bankruptcy to the Bank - know your limits.

Auction price always begins at $1, regardless of what combination of Colour Groups have been announced by the auction Entrants for this House(s).

The number of houses at auction is the amount by which house demand exceeds supply. If there are 9 houses and four players announce intent to buy (for a maximum of 1 Colour Group each) 13 houses. than an auction begins for 13-9 = 4 houses.

A bid by a valid entrant (above) is final once made. If an Entrant bids an amount greater than they can immediately pay from cash and from mortgaging undeveloped properties on undeveloped Colour Groups that entrant is Bankrupt to the Bank and out of the game.

The Player winning each House Auction must place all houses won on any properties of the one Colour Group announced by that player as destination when entering the Auction; in accordance with the normal placement rules for houses on a Colour Group.

There are two deliberate strategic considerations explicitly available to the players here:

The last Player(s) into an Auction have increased ability to control the size of that Auction.

It is possible, and allowed, to attempt acquisition of houses more cheaply than normal through strategic auctions. The Players have an obligation to protect themselves against such activity by being in a position to compete in Auctions. this is no different from acquiring Properties cheaply in Property Auctions.

This makes logical sense to me as the auction price would have to start at the price for the lowest property being bought for. You wouldn't want someone winning an auction and placing it on a property where the house should cost more than was paid for. For example paying $150 for a house that goes on a property where it should cost $200.

@JoeW: I never claimed or recommended that - but the other players know, and that adds the interesting additional game theoretic aspect in my mind. It's the responsibility of the other plyers to bid up the price of an auctioned house appropriately.

I am not saying you made any claims but just pointing out that even at auction you would still have to at least pay the minimum amount for the color group you are wanting to purchase it for.

@JoeW: It doesn't work that way, as i could enter bidding for the browns, as you enter for Matfair and pick up a house for $75 by outbidding me. Once an auction starts, each enrant must announce which colour group their purchase will be placed on. It can't be that only the firsts entrant is unable to get a house below the standard value.

If there is a large number of houses up for auction, and you don't want to spend the next half hour of your life auctioning houses, everyone should secretly write down a list of prices. The first house goes to the highest price, and that price is crossed out. Then the next, and so on. You could also have it be that the house goes to the person with the next price, but the price they pay is always the next highest price after that one (see Vickrey auction).

Isn't it funny that a game that has been around for lots of years. Still has major flaws in the rules. Maybe because nobody reads them and made uo their own. But it is funny that nothing can be found about this.

I think you misunderstood what I was trying to say. If someone is bidding for a dark purple property and someone else was bidding on a dark blue property the price of the house/hotel would start at the value of the dark blue property since that is the most expensive one being bid on. All I was trying to mention is you can't buy it for cheaper than it would be non auction.

Question : If you buy a house at “auction,” can you put it on any property?
Short answer : No
According to the
Monopoly 2020 World Championship rules
https://www.2020monopolyworldchampionship.com/hk/MWC%20Rules%20(Eng).pdf

RUNNING OUT OF BUILDINGS If the banker has no houses left, you must
wait for other players to return theirs before you can buy any.
If there is a limited number of houses or hotels left and two or more
players wish to buy more than the banker has, the banker auctions them
off individually to the highest bidder, starting at the lowest price
shown on the relevant Title Deed card(s). Note: You can only join in
the bidding if you have room for that house or hotel on one of your
properties. You can never buy a house or hotel to use later.

Therefore, if there are left a limited number of houses or hotels, and
at least two players want to buy some,
then the bank auctions off the houses, or hotels, individually.
The bank will fix the starting price at the lowest price shown on the relevant title deed card. In other words, each bidding player must first reveal on which property the house or hotel will be legally built, if it is won.
Conclusion : A player can win a house or hotel for an price that is lower than the price indicated on the title deed.

Good find. This is pretty close to what I surmised as the likely rule interpolation most consistent with the spirit of the other rules.

"Conclusion : A player can win a house or hotel for an price that is lower than the price indicated on the title deed." But this can happen only if another player with a cheaper monopoly tries to contest the house purchase. Otherwise, the first player will have to pay $200 for a house on Boardwalk, right? If that's the case, the person would the lesser monopoly might keep silent. A logical time for an auction might be if the last house was for sale, the Boardwalk holder wanted to pay $200 for it, and another person says, no, I"ll bid $250 for it, even for New York Ave.

This is an interesting question. It is not explicitly mentioned in the rules. But there is nothing in the rules prohibiting an auction if players want houses for different tiers. And it must have been if that was the case.
Besides, it is an auction so the bidders decide the value they want to pay.
There are some topics on BGG about house auctions and one person even asks the same question but it is never explicitly answered.


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Are there any simulators for Monopoly that meet my specifications below?
There are simulators for "deterministic" games like chess and Go that will estimate each player's win probabilities (probably using Monte Carlo simulation), and also combat resolution simulators for wargames such as Axis and Allies. I was wondering if there are simulators that will estimate your "win chances" in Monopoly, based on the positions that occur after a given trade.
Example: I won a game after giving an opponent the green monopoly in exchange for the maroons. I won the game because I had $1200 cash (and quickly built three houses on each) while my opponent had only $200 cash. (Consider the remaining properties to be "evenly" distributed, including two railroads and one utility for each person.) I would guess that the outcome might very well have been different if my opponent had the $1200, and I the $200.
This isn't a simulator, but it is a calculator that calculates the theoretical value of properties given various "states" of building development. The main thing that is missing is the role of players' cash positions in win chances, because more cash means that you can develop faster than your opponents.
Is there a simulator that can estimate my win chances given starting monopolies and starting cash, (and assuming that the other properties were evenly divided)?

To close voters. This is not a question about "game "recommendations." I have already chosen the game (Monopoly). This a question about game 'tools" Does such and such a tool exist (that meets certain objective specifications), and does certain calculations.(I have edited the title to make this clear.)

If it is closed, we vote for reopen. ;-). There are three Leave Open verdicts in the review queue.

The fact that there is randomness involved in monopoly should actually make it easier for Monte-Carlo tree search to give accurate results, not harder.

Using the calculator linked in the question, you can do your own rough simulators. The calculator already calculates the theoretical value of each roll in your making money from each configuration. The condition that "other properties are evenly divided" equates to "outside of the properties in question, the net gain or loss between the players equals zero.
The thing that is missing from the calculator is the cash levels. To make matters simple, you could invest $900 of cash in three houses each on the maroons (which is what I did), as still have $300 left for emergencies. Your opponent probably needed to retain all of his $200 cash for "emergencies." He could not buy as much as one house each for his greens (unless he mortgaged some properties, and he didn't do that in the actual game).
Let's examine the states, $300 for you, three houses on each of the maroons; $200 for him, no houses. According to the calculator, each of his rolls is worth $35 to you. It takes about 5.85 rolls (averaging seven on a 40 square board) each time around, which is about $205 dollars. That is (slightly) greater than his $200 salary, which means he is on the verge of defeat. Add more houses or build hotels, and he should be sunk.
With the money reversed, the story is different. You opponent could build two houses on each of the greens, deplete his cash, and rely on mortgaging property for his turn to turn needs. You could build one house each on the maroons only by mortgaging for $100 above your cash. Each of your rolls is worth $32 each to him (average expectation for the two houses on each of the greens) and each of his rolls is worth $4 to you (one house on each of the maroons). With a net difference of $28, each time around the board, you are on the verge of defeat, and will be sunk when he adds third houses to each green.

You're right that the linked site isn't a simulator, but it may be providing even more valuable information. That site provides calculated probabilities which is generally better than a Monte Carlo simulation, which is a technique used to estimate probabilities. The value of the calculation or simulation also depends on any simplifying assumptions used and how well these assumptions match your situation. Since you wish to only calculate based on Monopoly holdings, you indicate a willingness to use simplifying assumptions. I will also assume that you are playing until bankruptcy, advice may be different for a timed game. I suggest that the typical mid-game trade evaluation situation allows us to simplify away the current token positions of each player, so this makes the provided Markov based calculation tables applicable.
Your key concern seems to be a desire to incorporate each player's cash holdings, not just the properties involved. Post trade cash highly effects the game outcome. For this situation, I think the key metric to calculate is each player's expected-income-per-turn in the long run. This won't give a precise estimate of odds of winning, but it will be close enough for good decision making. To make the trade decision, need to evaluate the pre and post trade game states as outlined below to determine if the trade is in your best interest. Note some other trade might be in your best interest and could also be calculated.
For this evaluation process use the "Expected Income Per Opponent Roll on all Properties Assuming Preferred Long Jail Stay" tables. Using this table assumes you are in the end game state which most games will eventually reach.
Each player's expected-income-per-turn = + 28.1144 (from non property squares) - Lookup value from each unowned property + [number of remaining opponents] * Lookup value from each owned property.
As your question indicates, since income from unimproved properties is a minor factor, we can assume that this largely cancels out and we only need to do the above calculation for improved properties. Including railroad income for anyone with multiple railroads may also be significant.
A key challenge in this process is determining what level of improvement to use when looking up the value of each property. We need to determine where post trade cash will be invested. The best assumption would be that available cash would be invested in improvements with the quickest payback as per the "Expected Number of Opponent Rolls to Recoup Incremental Cost (Short Jail Stay)" table.
Any opponent with a negative expected-income-per-turn will need a good deal of luck to win the game. When multiple players will can have positive short term cash flow from expected-income-per-turn, you may also need to calculate the best case cashflow where properties are fully built up. A typical mutually beneficial trade will result in one player getting the better current expected-income-per-turn but the second player getting the better best case expected-income-per-turn. In this case the second player typically wins IF he can avoid disaster long enough to make the needed improvements (and isn't blocked by a housing shortage strategy) in order to eventually have the highest expected-income-per-turn.


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How does one determine the relative merits of the "4 to 1" versus "2 to 1" trade terms in Catan?
At first blush, the right to acquire a scarce resource for only two units of your "abundant" resource is an advantage over having to trade four units of the same resource. But because of "side" conditions, that is not always true in Catan.
There are five resources. Call them A, B, C, D, and E. Let's say that E is the scarce resource. You can either build a road followed by a port settlement to access either a "2 to 1" harbor or else you can trade at a "4 to 1" ratio (these are references to the required payments for the scarce resource ) with no strings attached. The "catch" is, at the "4 to 1" rate, you can trade any of the four other resources at that ratio, whereas at a "2 to 1" harbor, you can trade only one specific resource, say, D, for E, at the favorable 2 to 1 ratio. On the other hand, you do not have to build a port settlement to trade at the 4 to 1 ratio, whereas you need to do so to trade at the 3 to 1 and 2 to 1 ratios.
Maybe the question resolves into the following: You want to trade for E, and D is "only" your third most abundant resource (out of four), with A being very abundant, and B being more abundant than D. How do players determine whether they should aim for the 4 to 1 "straight up" ratio where they can trade A or B (or even D) at that ratio for E, versus needing to build a port settlement where they can only trade D at the ratio of 2 to 1?
Note: Someone pointed out that the original question about the comparison of a 2 to 1 versus 3 to 1 trade ratios was a duplicate of another question. I had planned a follow up question about the comparison of the 2 to 1 trade terms versus the 4 to 1 trade terms, and reworded the original question into this "followup" form, which I believe is not a duplicate. One important difference with the other question is that you do not need to build a port settlement to trade at the 4 to 1 ratio, whereas you need to do so to trade at the 3 to 1 ratio.

Does this answer your question? Are general 3-to-1 or specific 2-to-1 ports better in Settlers of Catan?

@Gendokari:The other question doesn't address the 4 to 1 ratio (and the fact that no port settlement is required at that ratio).

See meta question: https://boardgames.meta.stackexchange.com/questions/2009/is-one-distinguishing-feature-between-two-questions-sufficient-to-make-the-secon


text:
What is the rationale for a "forcing" 1NT with a range of 6-12 points?
First of all, my understanding is that no trump bids should be made within fairly narrow point ranges (2-3). Therefore, "6-12" looks like an awfully wide range for a single no trump bid.
Also, I feel that there is a world of difference between forcing and non-forcing. I prefer to use a 6-9 1NT bid as nonforcing, and opener can pass it there with a minimum. I would use a "two over one" sequence for 10-12, the upper part of the range.
So why do some bidders prefer such a wide "forcing" 1NT range of between 6-12 high card points instead of the above?

Do you want to miss game when opener has a big hand and a fit for your lower ranking suit which is their second suit?  Being +110 in 1S when you should be +620 in 4H costs you 11 IMPs.  Being -100 in 2S when you should be +90 in 1N only costs you you 5 IMPs.

@AlexanderWoo: I fixed the question by asking why people prefer a forcing 6-12 range instead of breaking it up into two ranges, 6-9 (non-forcing) and 10-12 forcing. Even a big hand can rebid with a non-forcing 1NT (but a "small" one isn't forced to.) Will you remove your downvote (if it is yours) and/or address my new question?

the answer is that most experts now prefer to play a 2/1 response as game forcing, and hence the invitational hands have to go in 1N.  People feel that the gains from 2/1 being game forcing outweigh the losses from putting 10-12 hands in 1N.

The forcing no trump response is sort of a hack. The key idea of the 2/1 game forcing system is that a non-jump new suit response at the two level to an opening one bid is forcing to game. In order to make that work, you have to take some of the hands that Standard American puts into 2/1 responses (specifically the non-game-forcing hands) and do something else with them. The 2/1 system chooses to put them into a 1NT response.
Why would you do that? Basically, 2/1's main advantage over Standard American is that it has improved accuracy in slam bidding. Because responder can often force to game at a low level, nobody needs to jump later in the auction with only moderate extra strength. This gives more room for slam exploration. The main disadvantage is decreased accuracy in partscore bidding, especially with regard to being able to stop in 1NT. Many people find that this is a good tradeoff at teams, and fairly neutral at pairs, so they play 2/1 instead of SA.
As to the "three point range" aspect of your question: All else being equal, it is good for one hand in the partnership to be able to show a balanced hand in a narrow range. That is why no trump openings and rebids by opener tend to show a balanced hand with a 2-3 point range. On the other hand, a 1NT response to an opening bid doesn't even promise a balanced hand (even in Standard American's nonforcing 1NT response). The forcing NT response asks opener to further describe their hand, rather than showing a specific strength or shape. While neither partner is yet captain, responder knows more about opener's hand than vice versa, so opener should describe further while responder looks for sufficient information to take full control of the auction.

Nicely described, though I'm going to nitpick "and fairly neutral at pairs". IMHO, it's less about being neutral at Pairs and more about team games being the prestige events at championships (perhaps because clients do better in them?). Thus systems are designed for team (and rubber) versions of the game, and the rest of us (non-experts) follow along because it's better than trying to design our own systems from scratch. It's over a generation ago now, but Barry Crane certainly proved that one can do very, very, well, even in team games, with a system designed for Matchpoints.

I agree that teams being prestige events is why some pairs play the same system at IMPs and MPs, but many club players who never play anything but pairs also play 2/1. I think it's fairly neutral at pairs compared to Standard American because while some partscore hands will come with a worse result, the increased accuracy at game and slam bidding can make up for those.


text:
How flexible is the six point response rule in bridge?
If partner opens one of a major, say one heart, I was taught that a responder could raise to two hearts with three of the suit and six high card points, or bid a new suit "one over one" (e.g. one spade) with six high card points and four of the suit.
But I often like to raise to two with as little as "four and four" (that is, to two hearts with only four high card points but four hearts instead of three. This is particularly true if I have the queen of hearts, because a queen that's a "filler" in partner's suit is worth more than two points.
I also like to bid "one over one" with "five and five" (only five high card points and a five card suit), say, one spade with KQxxx, or AJxxx and no side honors.
Finally, I like to pass with a "weak" six or even seven. That might be something like (s) Qxx (h)xxx (d) Qxx (c) QJx, that is all "quacks," no aces or kings, and no honors in the opened heart suit. Or (s)xxxx (h)Jx (d) QJx (c) QJx, again all "quacks," no honors in the four card suit, and no real support for hearts.
(All xs are 8 or lower.)
Are any or all of the above reasonable postures? Or should I stick more closely to the six point rule because of what partner might or might not have?

It's expert standard these days to frequently respond with fewer than 6 points and a reason to do so.  Majority expert opinion is that one should respond on something like Kxxxx in spades, a singleton in partner's opened suit (especially if it's a minor) and nothing else.  Many experts will respond on even less.
Raises are similarly aggressive; Qxxx in partner's suit and a singleton somewhere is more than enough to raise (to 2, or to 3 if you've agreed that is a weak preemptive raise, or to 4 at favorable vulnerability).
On the other hand, you MUST respond with 6 points.  If you have Qxx xxx Qxxx Qxx, and partner has AKx AKQxxx x Kxx, you have just missed a game by passing.  If you have Qxx xxx xxxx QJx and partner has AKx AKQxxx - Kxxx you have missed a slam by passing.  (Arguably the second hand is a 2C opener, but probably not.)
EDIT: And there is no downside to responding with these hands.  If you're going down in 2H but not in 1H, then going down in 2H is still a good score because the opponents are making some contract.
Bridge experts have been bidding more and more as they realize that bidding (rather than passing) has value beyond helping your side find its best contract; frequently bidding is important because it makes it harder for the other side to find its best contract, and sometimes it gets your side out of a bad contract into a less bad one.  As usual, if you're playing in a game where your opponents frequently mess up without your help, calculations are different.

Basically, it looks I have the flexibility to bend the rules "downward," but not to pull the requirements "upward." If I have Kxxxx in spades, the fifth spade and the singleton brings me up to "five."

@TomAu: I don't know of an expert who counts distribution points rather than using distribution as a non-numerical factor in hand evaluation.

I believe that Goren did, at least under certain circumstances. I'm following his (old) playbook.

@TomAu - It's what Goren taught in his books, but I don't think he actually used it at the table himself.

@AlexanderWoo: I believe you're mistaken. My impression (coming from an older generation) is that Goren was actively trying to perfect his system by discovering edge cases, and thus deliberately did use it at the table - as far as it went - in search of ways to enhance it. Goren was frequently kibitzed by novice and intermediate players, and it could have been embarrassing, or even monetarily counter productive, to be found bidding against his own system. Goren also had the luxury and benefit of playing frequently with Helen Sobel.


text:
Would you overcall, double, or do something else with the following strong but "offshape" hand?
You are vulnerable versus not, when your right hand opponent opens one heart. You are sitting on the following "powerhouse," but one that is "offshape" for the calls you want to make:
(s)AK54 (h) J43 (d) Q6 (c) AKJ8.
This hand is fine for a takeout double of one diamond, but not one heart. Even so, an expert (Frank Stewart) recommends doubling with this hand because the extra high card points (18 in total) may well compensate for the bad shape. The actual bidder opted for a 1 spade overcall with four cards in the suit, ended in a "Moysian" 4-3 fit when responder cue bid two hearts, and made it because of his "extra" strength.
Change the two black kings to tens (giving me only 12 high card points) and I would pass, and I might do so with 15 (only one black king). Do the extra points give the bidder "leeway" to either double or overcall with an otherwise unsuitable hand? If so, is either "double" or "overcall" or something else the better choice?

I would downgrade a hcp and bluff a heart stopper and bid 1N.  (Maybe partner has Qx or Txxx in hearts and wouldn't think it was a stopper.)  I don't think double is wrong.  I don't like pass or 1S, both of which are severe underbids.

I agree whole heartedly. The modern approach is to bid the shape and strength with 1NT as often as possible, since Partner has many varied tools available for exploration if NT looks unsuitable from his side.

I consider xxx a "stopper" for a 1NT bid (Jxx is "gravy" if opposite Qx or Txxx). If partner has the same, the chances are 62% that opponents will have a 4-3 suit. Hopefully, with 24-25 hcps in 3 suits, there will be nine tricks.

@TomAu - Not if they opened 1H promising 5 of them!

When the hand belongs to your side, it's important that you're in the auction. You should either declare a contract or get enough equity from defending a contract declared by opponents. When you have a balanced 12 count and RHO has opened, it's slightly less likely for the hand to belong to your side than theirs. When you have a balanced 18 count and RHO has opened, it's very likely that the hand belongs to your side. That means that you can afford to stay out of the auction on a balanced 12-count if you don't have a clear action. With 18 HCP, you have to get into the auction so that you don't just get stolen from.
With AKxx Jxx Qx AKJx, you don't have an appropriate overcall, so you have to double. So the main question is how you plan to deal with partner's potential actions. Let's consider various auctions that start (1H)-X-(P)-??-(P).

After 1S, I think 3S is the right call. You can't insist on game but I think game is still possible.
1NT should give you the confidence to raise to 3.
2C is interesting. I think there are a range of options here, in part depending on scoring. I'll abstain from recommending an action.
2D: There's no game here. Pass and keep the contract low.

Any other action by your partner is stronger and should lead to some sort of game.

All the reasonable actions (double, 1S, 1NT) have their pros and cons, and can work out.

I would likely double here. The extra strength does give you some protection, Stewart's argument is not without merit. The worst that can happen is that partner bids 2D and is left there, when you belong in 1NT. Can't win them all.
1S also has merit. Partner will often raise with 3 card support, particularly with short hearts, but any heart ruff will then be in the short trump hand, and that is good. Those AK of trumps leave you a great degree of control when declaring. The danger is that the opps trumps may split 51 making game level problematic.
1NT is also a possibility. Partner will not be happy when they raise to 3NT with AKJxxx in diamonds, a singleton heart and out, and the opps cash five or six heart tricks (5D looks good and six has some play with another black quack). But that is just one hand. On many others you can explore game possibilities, and may locate a 44 spade fit.

One reason I prefer double (or 1S) to 1NT is that the hand may play better from partner's side (give them KTx in hearts for example). Bidding 1NT more or less guarantees that I will declare the hand. That may be better in some cases (defence is more difficult with the weaker hand displayed as the dummy), this is just another concern.

Let's say you overcalled 1S.  Would your partner make a bid with S: xx H: QTx D: KJxx C: Qxxx?

Point taken @AlexanderWoo. Playing in a Moysian is NOT the chief problem with 1S. Some players might bid 1NT over 1S with your example hand, I think it's close but might pass. Many would bid 1NT over my double, and the example hand would surely act. But many would also invite over 1NT with that hand. Depends on the exact range of your 1NT overcalls, I suppose. Goren had 16-19, my partner and I play 15-18.


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Is it ok to open a "weak two" with a decent six of a suit and a "weak" four card side major?
With equal vulnerability,  and a holding like (s) KQ9753 (h) K432 (d)xx (c) x, I would pass in  first or second position, so that others can bid and I can respond or overcall. I don't mind doing this with a weak but "near average" holding (8 hcps vs. 10). Partner figures to have 11 points on average, we could have "19," and a good part score, or even a game in either spades or hearts. My command of the major suits could make up for the slightly inferior point count.
But with a holding like (s) KQ9753 (h) 5432 (d) xx (c) x, I would want to open with a quasi preemptive "weak" two because I don't have enough defense to stop an opposing slam on my own if partner has nothing. Also if I have four* high card points, and the remaining average around the table is "12," partner and I will have "16," leaving 24 for the opponents. And I consider my 5432 in hearts more like a Qxx than a four card holding.
Is it ok to open a "weak two" like I do if I feel I have "no" defense? (I would be "undecided" if my holding were (s) KQ9753 (h) J432 (d) xx (c) x.)
*I would open a "weak two" with as little as Axxxxxx, QJTxxx, or KQxxxx. This is a little weaker than KQxxxx (two out of the top three), but my rule is "one sure honor trick," that is, a six card suit headed by an A, KQ, or QJT, (but not KJ9, which has "holes" that can be finessed).  Goren treats QJT like a "four" point holding.

This is totally dependent on your partnership style, primarily how constructive or destructive you want your preempts to be.  Your considerations are valid.

Call for the director. You seem to have been dealt 14 cards :-)

Other than that I agree with Alexander woo and your own thoughts. With the first hand: You have the boss suit, so you rate to get another chance to show it. Also you have both majors, so giving partner a chance to show hearts at a comfortable level may pay off. With the weaker hand I would be less worried about missing a heart fit. Partner needs more for you to have a game, and will be able to show hearts when that is the case. Also, you have no entries in the heart suit itself (ruff entries possible), so the hand will be less flexible in a heart contract.

@JyrkiLahtonen: The club suit should have only one x, not two. Fixed. Thanks for your help.

This is up to you and your partner.  Partnerships - including world-class partnerships - have different agreements about this.  Note your agreements about what is allowed for a weak 2 not only affect how partner might respond with various marginal hands but also should affect what conventional follow-ups you play.


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Could leading one of dummy's bid suits be a good idea?
Vulnerable versus not, and sitting West, I held (s) AQ54 (h) K3 (d) T85 (c) KT87. With North opening the bidding, and West and East passing throughout, the bidding went:

North    South
1 spade  2 diamonds
3 clubs  3NT.

I actually led the d5, which seemed like the safest lead, but got us a bottom on the board at matchpoint duplicate. It crossed my mind to make the "bold" lead of the low card of the unbid (heart) suit, but felt that it was too bold. With the benefit of hindsight, I thought about leading one of dummy's bid suits, rather than declarer's, probably the c7. Could this be a good idea under the circumstances?

Was 2D game forcing?  Did 3C show extra strength?  What was the form of scoring?  Also, it would be good to see the whole hand so we can tell if the diamond lead caused the bottom.

You're looking to find Partner's J; though possibly a Q, and possibly a measly T. So what you are looking at is most likely all prospects for the defense, and you're endplayed at opening lead; except Declarer doesn't know that yet. No way I'm leading a Diamond to set up closed hand's (likely 5 card) Diamond Suit; Partner has no entry to Hearts even if they set up; and my Spades are all on side. So yes, I'm definitely leading a Club on this auction.
Which one is harder to judge; but since I dread seeing the 9 come down in Dummy the Club 8 is hitting the table in tempo. Play to Trick 1 may be the only meaningful decision Partner has on this hand, so I want to make that as easy as possible to get right.
There being no safe suit to lead on this hand, I don't see any reason to distinguish between Pairs and Team play in this case. I'm just hoping to pull a fast one on Declarer quickly before he learns anything about our hands.
The above is premised on a Yellow Card-ish bidding system with 2D being 2-over-1 Forcing and 3C showing either length or strength in the suit but likely not both. I expect 5-3-2-3 or 5-2-2-4 distribution to come down in Dummy and Declarer to have something like 2-3-5-3.

While understanding opponent's bidding agreements is pretty important to give advice for this specific hand, the answer to the question you ask in your title is "yes, it can be." Let's look at a few examples.
You hold Axx xxxxx xx xxx. RHO deals and opponents have the following uncontested auction:
     1D
1H   1S
2C   2H
2S   3D
3S   4D
4H   4NT
5C   5S

Under opponents' agreements, RHO has shown something like 4=3=5=1 shape with good diamonds and extras, while LHO has shown 4-4 or 4-5 in the majors with a heart control and extras. LHO has also shown one keycard. Looking at your hand and listening to the auction, partner likely has the club A and a heart singleton or void, and nothing else. To defeat this contract, you'll need a heart ruff. Lead a heart, win the first round of trumps, and continue a heart. Partner will get a ruff and cash the setting trick in the club ace.
Now imagine the same auction, but you hold xx x xxxx Axxxxxx. Lead a heart hoping that partner holds the hand above.
OK, so those two hands show that one reason to lead dummy's suit is to set up a ruff.
OK, now you hold xxx Kxxx xxxx Kx. The auction is
LHO  Ptnr  RHO  You
           1C    P
 1S   P    2NT   P
 3NT  X   all pass

Partner's double asks you to lead dummy's first-bid suit, so lead a spade.
Now you hold xx xxx KQJT9 Axx. LHO deals and opponents have the following uncontested auction:
1D  1H
1S  1NT
3NT

Lead a diamond. You expect to collect 4 diamonds and the club ace.
Now you hold Ax KQJT QTx J9xx. The opponents have a Smolen auction:
    1NT
2C  2D
3H  3NT

LHO has shown 5 spades and 4 hearts. Lead a heart to attack dummy's entry. With luck, dummy is something like KQJTx Axxx xxx x. You can hold up the spade ace one round and watch partner's play to figure out which minor you can safely lead away from (perhaps partner has the club Q or ten, or the diamond J or K). Then declarer will be forced to play the minors from their hand, eventually giving you the setting trick.


text:
Is it OK to make an "offshape" bid if you can handle any likely response?
With no one vulnerable at atchpoints, left hand opponent opened with one heart. Partner passed, right hand opponent raised to two hearts (both of them had minimums for their bids).
I passed, holding ♠87 ♥AKJ2 ♦ AKQ9 ♣QJ3, because I was "stuck" for a bid.
I considered doubling for takeout, but feared that I could not handle the likely two spade "forced" bid from my partner. With the benefit of hindsight, it might have been OK, since partner would bid his "cheapest" four card or logner suit (he could not have more than one heart given my holding and the opponents' bidding).
Partner actually had JT96 of spades, and would have bid them, in which case I would bid 2NT, probably going down one. This contrasts with the usual offshape takeout double when you have a big hand and a five card suit to run to.
The other bid worth considering was the unusual 2NT, which seemed promising, given that partner's distribution was 4-1-4-4. I didn't have the normal 5-4 or better distribution but perhaps my extra points would have compensated.
We got a bottom for selling out so cheaply. Was either double/2 NT or 2NT (unusual) a better option, even offshape, than pass?

Agreeing with ruds.  A different POV on how to think to get to that conclusion.
Assuming the opponents "have their bids" (i.e. they're not under 50 or play Precision, where the opener could be 10 and raiser on 2-with-a-stiff), you can see what's going on.  11 or 12 on your left, 6ish on your right (do they play constructive raises, so it's 8ish on your right?), 21 in your hand - partner has nothing.  If you're really lucky, he has the ♦J or the ♥Q (stiff, of course), or the ♣Q with the A in opener, so you can get to the board once.  If you're not "really lucky", you're playing this out of your own hand, with many of the cards over you, and you might make 6 tricks.
Of course, with that heart suit, you might make the same 6 tricks defending 2♥, even "endplayed at trick 2".  Here, the spades are actually useful - as exit cards!  Plus you have the hope that partner being on lead once can make a useful lead through strength (of course, she could lead a spade and take away one of my exits.  Oh well).
Now, if they are the ultra-moderns, and partner does have 7 or so of the finest and a stiff or void heart, she might decide that "they don't play two of a fit at matchpoints" and double.  And you'll know what to do then! (I know, can we get it for -500 into the -430s of the people that doubled-and-bid-NT?  Isn't matchpoints fun?)

Pass is the correct bid. If you got a bottom, it is because opponents were unusually aggressive at your table, or because you misdefended.
Your hand screams defense. You are balanced. You have excellent values in their trump suit and a small doubleton in the unbid major. When you picked up your hand and before anyone had a chance to bid, you would have had reasonable expectations of playing in 4H your way.
In normal circumstances I would expect to get +50 defending 2H and -50 (at least) in 2NT or 3C.

Maybe we misdefended. Partner led the ace of clubs (his one other face card), which declarer ruffed, and that set up dummy's king, allowing them to make two hearts. Given that ace (which I had not counted on), we would have made 2NT instead of going down one. The opponents are very aggressive, and this time they got away with it.

(a) How did dummy have the club King when you had it as well? (b) There's a reason that we don't lead unsupported aces against a suit contract.

My club holding was QJ3, dummy had the king. My mistake. Sorry.

@TomAu You were unlucky. But there isn't really anything you could have done about it in the auction, you can't assume the opponents are always overbidding.


text:
Did I act reasonably by raising following my takeout double?
All vulnerable at matchpoints, right hand opponent opened one club. I doubled (takeout) with the following: ♠KQ75 ♡ T752 ♢ AKJ9 ♣ 3.
Left hand opponent passed, and my new partner bid one spade (forced) with the following: ♠T843 ♡ K86 ♢ 842 ♣ A95.
Right hand opponent passed. I raised to two spades, partly as a mild game try.. Left hand opponent passed, and partner rightly passed, since he did not have the hand I was hoping for.
After the hand was over, he complained, " You needed to have 16 points to raise to two, and you only had 13."
I said, "I put you on a maximum, 6-7 because of the opponent's tepid bidding. (if partner had as few as "5," the (aggressive)opponents would have 22, and I couldn't imagine them remaining silent).
I counted extra over 13 for my club singleton. While I'm glad that he passed with his actual hand, I thought that we had game chances if he had something like ♠T8643 ♡ K8 ♢ 842 ♣ A95. These chances would have been even better if you changed his king of hearts to queen of diamonds (one point less in his hand but four sure diamond tricks).
He made three spades, and got us a top, because other pairs with our cards had 1NT bid and made against them. (I was frankly surprised that our opponents stayed silent with "20," and my 2 spade bid was partly pre-emptive against left hand opponent. Afterward one of the opponents defended me by saying, "I don't see what you were complaining about. You made an overtrick over two spades, and it seems like Tom had a point when he thought you could make game with the right distribution."
I believe that it was Marty Bergen who said something like, "you can try for x (e.g. game) if partner's maximum will allow you to make it, to give partner a chance to bid it." Is that principle operative here and if so, do these hands qualify?

You have a very good 13 for a takeout double of 1♣ - 4-4 in the majors, singleton club, all cards "working", even the ten of hearts.
Traditional expectation is "double with an opening hand counted as dummy points."  With that view, your hand is closer to 16 than 13.
Can you make game opposite a maximum?  Sure - Partner's hand isn't even close to a maximum, and the ♣A isn't pulling its full weight.  Shortness in hearts, with the trump A and the diamond queen, likely leads to game right there.  But that's a magic hand.  They exist, and the "perfect minimum" (in this case, the "perfect minimum maximum") theory applies.
But let's look at the alternative: partner has ♠Jxx ♥Qx ♦ xxx ♣xxxxx.  I've even given him a three-count, could even be 4 (♥K instead of the Q) could be more with wasted club quacks.  That's an equal "magic hand" to the other one, just the wrong kind of magic.  You might make only 5 tricks; and you almost certainly won't make 8.  Sure, it's much more likely you have a 4-4 major fit than if partner responded 1♥ because he bypassed both red suits, but in "White Queen land" (as opposed to "magical Christmas land" - same weather, different magic), you could be facing this.  The opponents likely can't make any game; -200 is still the "matchpoint death score", and you could easily get there undoubled.
Should you look for game?  I wouldn't do it, but I don't think it's Wrong.  I think it's dead minimum, though - you're looking for a well-fitting 19-21 point game, and you can't really ask what you really want to know - "how many heart losers do we have, pd?"  But if partner plays the spots off the cards on the regular, and/or you're playing the pair you can pretty much guarantee will give away a trick in defence (and won't double you, even in 3), well then.
Of course, one of the ways expert declarers win at matchpoints is that 1♠+3 beats all the 1♠+2s exactly as much as 4♠= does, while not losing to them when even they can only make 9 tricks.  Remember your goal at matchpoints is not to get the best score possible, it's to get a better score than the other pairs.
Now all of this is assuming you're getting a free run at it, and will be allowed to play 1♠.  I don't believe that for a minute, but it could happen (and I'd probably hate it if it does, because the trumps are 4-1 at best).  You can pass this, and come back in with 2, in a way that if they decide they want to compete against "2 of a fit", you won't want to come back in at the three level.
Having said all of that, declarer's comment when dummy came down was bad. Giving the defenders hope during the play is a fast track to their best defence (and, again, that overtrick might make all the difference!)  That's a natural reaction we all do, sure, but a habit it's best to break.
"I expected a little more for the raise, partner, I might have gone on with a better hand and have no play" after the play (better yet, away from the table after the round) is just explaining to you what he expects to see and counts on for his decisionmaking.  And frankly, the answer I keep harping on, here and elsewhere, is "doing what partner expects is better than being 'right'" - and if partner wants 16 Miltons for this raise, to judge correctly, then pass him next time with 15.  But the right time for this discussion is when the opponents aren't there to "support you", and definitely not when the opponents are still concentrating on taking tricks.

It was partly a matter of "playing the players." We got a top on the board because other pairs with our opponents' cards bid and made 1NT. Our opponents were aggressive, and I wanted to head off a competing bid by LHO. If my partner had as few as 5 points, opponents would have had 22, and it is INconceivable that they would have refrained from bidding--in fact, I was surprised that they kept quiet with "20" when all their counterparts bid 1NT. I put opponents on 18-20, and did not rule out the possibility that partner had "bid shy" by not raising with 8 points, perhaps ♠Axx ♥KJ ♦ xxx ♣xxxxx.

Your opponents are never playing 1NT. You're always going to bid 2♠ eventually, right? Do you think they're making 2NT when you know what to lead?  I like AWoo's ideas, but I'd want to have it very clear, in advance that we're playing that.  But you will get another chance.

Frankly, I hate the admittedly still standard agreement that a raise to 2 here promises extra strength.  I think a raise to 2 here should just promise 4 card support.  Good opponents will never let you play in a fit at the 1 level, and keeping the opponents from finding a fit at the 2 level and then finding 3 level bid over your 2 level contract is just that important.  -100 is better than -110 (if you go down in 2S and they make 3C or 3D), and +110 is better than +100 (if you make 2S and they go down in 3C or 3D).
There is a downside, which is that you've got fewer ranges of invitational bids, and that means you'll make the wrong decision about playing game more often.  Especially at matchpoints, that's a cost I'm willing to play in order to keep opponents from getting competitive bidding correct more often.
However, I do sometimes play treatments that I hate just to keep partner happy, and partner sometimes does the same for me.


text:
What does it mean when the laws say that a forcing 1NT response cannot guarantee invitational values?
"Invitational" usually means 10-12 high card points. A forcing 1NT response typically has a range of 6-12 points.
I consider it unwise to bid a forcing 1NT with only 6-7 points unless I have four good hearts over a 1 spade bid. Does the rule mean that "some" of my responses have to be in the 8-9 point range so that I don't "guarantee" the 10-12 point invitational range when I bid a forcing 1NT?

Please note that almost no events are played under the Basic chart.

What do you do when you hold xx AQxxx xxxx xx and partner opens 1S?

@AlexanderWoo: I bid 1NT reluctantly because of the fifth heart and because AQ is 1.5 quick tricks. But I pass xx AQxx xxxx xxx or xx AJxxx Jxxx xx  or xx KQxxx Jxxx xx. I would bid with xx KQJxx xxxx xx, because the KQJ sequence is worth 7.5 in my book., even more than xx AQxxx xxxx xx

If you pass xx AJxxx xxxx xx, you're missing game opposite AKxxx KQxx x Axx, a very good opening hand but not nearly a maximum 1S opening.

@AlexanderWoo: Maybe I should give more leeway when the suit in question is hearts. But I would never consider forcing 1NT with  xx xx AJxxx xxxx, and probably not with  xx xx AJxxx Qxxx that is, when the suit(s) in question are minors. ,

and now you're missing a slam when partner has AKxxx x Kx AKxxx (though admittedly the one of the opponents might come in given they have 10 hearts between them)

You are referring not to the laws, but to the ACBL's convention charts, which govern the conventions that are legal to play in ACBL-sanctioned events. In the Basic chart, which is designed for events with very inexperienced players, any bidding agreement not explicitly allowed is forbidden. One allowed agreement for responses to the opening bid reads:

A Forcing 1NT response to an opening bid of 1H or 1S. 1NT cannot guarantee an Invitational or stronger hand.

In this document, "Invitational" is defined to mean "A hand sufficiently strong to indicate that partner should bid game unless partner has a minimum."
Thus, the meaning of this rule is that in events governed by the ACBL Basic Chart, an agreement about  forcing 1NT response to an opening bid must include some hands that are insufficiently strong to indicate that partner should bid game with slightly more than minimum values.
On a side note, you are wrong to shy away from a forcing 1NT response with 6-7 points. The forcing 1NT response to one of a major in 2/1 should be made with all hands that would respond 1NT in Standard American, as well as some hands that would take a stronger action in SA.

I am BARELY willing to respond 1NT with six points if it were non forcing. (Partner can pass and leave us at the one level.) I'm "out" if partner is forced to the two level. With 7, I  would bid 1NT with AKxx or AQJX in a suit, but pass if I had, say three queens and a jack.

Do your partners open a lot of balanced 10-counts? Do they open 2C with 19-counts? With Qxx xx Axxx xxxx, passing 1H is losing bridge. You'll probably end up in 2C or 2D across from a minimum, but when partner holds KJx AKQxxx x AQx, aren't you sad to be in 1H instead of 4H?

If I were your partner, I would open 2 clubs with KJx AKQxxx x AQx. (Eight playing tricks that could get to 10 with the right three points (Q of spades and J of clubs) from responder). I am also experimenting with an all-purpose 2NT bid for that hand to pull in the 5 and 6 pointers. My partners open a lot of UNBALANCED 10 pointers.

So you stretch to pass with perfectly serviceable minimum responding hands, and counteract this effect by stretching to open 2C with perfectly serviceable 1H openers. I think you fear 18-point 2-level contracts too much, and don't bid slam aggressively enough after 2C openers.

One of the downsides to passing is that you encourage the opponents to come in, and now they find their fit and get their +110 rather than +100 or -50 instead of -80, or even their +110 instead of -110.

@ruds: I don't consider KJx AKQxxx x AQx, a 19 point hand. More like 23 points, after counting 2 extra points for the sixth heart, and another 2 points for the minor suit singleton, and worth a 2 club opener. Contrast this with KJx AKQxx xx AQx (five hearts and two diamonds), which I do consider 19 points (maybe 20 counting 1 point ofr the diamond doubleton.

I mean, you can do that if you want. It's not against the laws of bridge, although the hand doesn't qualify as Very Strong in the ACBL convention charts. I just think it's unwise. It's a 6331 pattern, not some exotic distributional freak. It's almost half the deck in terms of points, and it has the expected 2 aces and 2 kings you would get with half the deck. The honor structure is good, and it would be reasonable to treat it as a bit stronger than 19, but I think 23 is way overstating the strength.

I would consider 2C on Axx AKQxxx x AQx, but not KJx AKQxxx x AQx.  The first is 8.5 tricks assuming hearts split and you can get to dummy; the second is 8 (7 and 2 halves) and even then that requires 2 dummy entries.  Joe Grue did open 2C two days ago on 17 hcp, but that was a solid 9 tricks: https://vugraph.lovebridge.com/screen/usbc/436932?screen=replay&ns=439916&board=47&round=4

(cont) If you opened 2C on KJx AKQxxx x AQx, I doubt you'd be happy with partner driving to slam with Qxxx x AJxx Kxxx as Brad Moss did with an equivalent hand, though Axx AKQxxx x AQx isn't much better for slam opposite that.

The seventh spade that Joe held makes the suit much more likely to run (in addition to representing an extra trick). Two outside aces is much better than an A and a KJ, as you point out. That hand is considerably closer to an "exotic distributional freak". Good find!

@ruds, two comments.  1: "not Very Strong" for 2C only an issue on Basic/+ (not allowed).  Legal (and Alertable) on Open+.  2. Tom's hand is arguably Very Strong (5 controls and 8.5+ tricks with even breaks).  It's certainly better than the "overstrength preempts" that are the reason for 1.  I think as well as the constructive issues, he'll be very happy when it goes 2C-(2S)-p (GF)-(4S) (or 3D-5D, more likely). I have been less enamoured of "upgrading into strong bid" as days go by.

The reason why this is not allowed on the Basic charts is that it allows responders 2/1s to be non-forcing - not just "not GF", but passable.  1NT is bid with any invitational or better hand, the responses are based on it guaranteeing invitational values (we're forced to 2NT or suit agreement at the 3 level, so lots of room to, usually artificially, show hands), and 1♥-p-2♦ is "6-9, to play opposite a minimum with some diamonds".
It is believed by the (ACBL) Competition and Conventions Committee that systems with that style are so unusual and so different in thinking patterns that they would gain against newer players simply by confusion, not by being better, and we don't want to confuse newer players.  Play in the open, play on the Open Chart (or even Basic+, effectively "not Gold Rush or I/N"), and we consider you good enough that you will be able to resolve that confusion (in time, at least).
As to why for 40 years it was disallowed on the General Convention Chart (that 90+% of games were run under) - well, that's another story.  One I think all the people involved in now are dead or at least no longer playing bridge.  One I won't go into here.  If you care, start your investigation with "breakthrough system bridge".


text:
Do good bridge players open one diamond and rebid two clubs when they are "weak?"
With no one vulnerable, partner opened 1 diamond after one pass. I bid one heart with the following:
♠ J985 ♡ AT852 ♢95 ♣ A9. Partner rebid 2 clubs. I tried 2NT, thinking that partner had the minor suits covered and I had the majors. We went down four, and I was surprised so see that partner had bid with  ♠ A6 ♡ Q ♢KT763 ♣ J7532. I wouldn't open with such a weak hand, but if I had, I would "sign off" at 1NT (non-forcing).
I had considered partner's sequence "somewhat strong," and put him on a minimum of something like ♠ A6 ♡ 2 ♢KQ763 ♣ QJ753. We would still have gone down one or two, but that would be better than down four.
A number of people in our club open "light" with 5-5 and 10 high card points even in first and second position. (And I didn't feel that partner had a full "10" because of the "stranded" Q of hearts and the doubleton spade ace, both outside his main suits.) Is this peculiar to our club or are players "generally" opening this way? And if they do, would it have been better for me to bid two diamonds rather than 2NT on my second turn?

Bridge is a partnership game.  You're not going to get better at bridge without regular partners with whom you have discussed these matters and made agreements.  (Also, if the state of your bidding agreements is that these matters are undiscussed, I cannot imagine your lack of carding agreements!)

I agree that 1NT is nonforcing, but so is 2C! A new suit by opener is not forcing unless it is a reverse or a jump.

@AlexanderWoo: I play casually on a "round robin" with just about everyone in the club. For social reasons. I'm placed in a position where I have to play the "partner," not my cards.

That 1♢ opening is laughable

@TomAu - then you shouldn't be asking us these questions; you should be asking your partner.  And if your partner doesn't care enough about bridge to discuss this, then your options are to not care about it either (when playing with them) or to stop playing with them.  It is futile to care about your results playing with a partner who doesn't.

@TomAu: Sort of agreeing with the above comment.  You may be "having to play the 'partner'", but your questions are frequently "was I wrong, or partner"?  Which won't help - because that's not playing "partner".  If you have to "play partner", then learn how to work out "partner", and how to "play partner". Or - and this is a serious option - become "partner" yourself, state your preferences, and make partner play "you" - at least in things you find yourself inflexible on. More fleshed out at the end of my answer.

@Mycroft: That's helpful.

"How do I 'play partner'?" actually sounds like a good question for this site - if it can be phrased in such a way as to not be closed as "opinion-based".  I also would note that it doesn't have to all go one way.  I will play partner's preempt style, for instance, whatever it is; but I insist on "simple" carding agreements (no coded 9s and Ts, no odd-even discards, etc).  I try to avoid multiple-pattern conventions like Bergen Raises or 2-way Drury with one-time partners, in case we happen to know them differently.  And I'm the flexible one, because I'm usually "the spare".

I've heard of this. It's the kind of bidding practice that your partner really needs to make you aware of in advance.

Even if this is a bad contract to end up in, I feel like it should be possible to take more than just the three Aces and ♢K.

I think your second bid should be 2D.  A rebid of 2N should promise an invitational hand, and I don't think that hand qualifies, particularly since you have a misfit (and hence partner's 5th diamond or fifth club is less likely to set up as a trick).

A rebid of 1N should promise a balanced hand.  A hand with a singleton (particularly a singleton honor) in partner's suit is sometimes okay with no good other bid, but a hand with a singleton and a doubleton is not.  The proper rebid on partner's hand is 2C, which should not promise a stronger hand than 1N, just a more distributional one.

Opening 10 counts like that can work, particularly at matchpoints, but I would consider that unusually light except in a partnership that has agreed to open light.  (In my Precision partnership I would open that 10 count all the time except at unfavorable, and sometimes even at unfavorable.  In my modernized-Kaplan-Sheinwold partnership I would pass always.)

Playing usual in North America 2/1 methods, I would prefer to open 5-5 10 counts only if the values are concentrated in the long suits.  But this is a matter of partnership agreement, and I'm happy to do what my partner wants.

I needed to ask the question to get a sense of whether this was "modern" or "unusual" bidding.  Even for my club, this is extreme. A week ago, I had an open following the same sequence with x xx AQxxx KJxxx; 10 points but highly coordinated. Here, I'm dealing with a partner who has no idea of a "good 10" vs. a "bad 10." To him, "ten is ten" and "five cards is five cards." Now that I have this sense, I can deal more effectively with this an other partners.

I'm also likely to open a weak 5-5 if the suits are majors. When your suits are minors, the usual goal is a NT game, which usually requires full high-card values because you need to take your tricks quickly.

In addition to what @Alexander Woo says, I disagree that the 5=5 minor hand should rebid a "limiting" (not "signoff". You're unlimited) 1NT.  Treatments (and system continuations) vary about whether 1NT with a singleton in partner's suit is acceptable, but:

If you're on the side of "singleton is okay", it should be a hand that "looks like balanced" if that singleton heart was ♥62.  Opener does not "look like balanced", it looks like a hand that wants to play in one of their suits (after all, that's why they opened it, right?  The strength certainly isn't in the HCP, it's in the shape - and that works in a suit, barring a good fit and cards in your hand).

side note, the other reason you don't want partner to "sign off" 1NT is that you will play him for 12-14, won't you?  If you raised to 2NT with a 4=5=2=2 11, or 3NT with a good 12, and went down three or four, you'd be just as questioning of that rebid as you are of 2♣ on this hand.  And with good reason.

I'm on the side of "singletons are not okay" (admittedly, for reasons outside the scope of this question).  But especially if you are also not a fan of "raise on 3", or minimize raises on 3 by requiring ♠x or xx or the like, hands like yours should be expected and able to sign off (yes, this time it is; 1NT has limited partner's hand) in 2♥.  After all, you frequently could have a 5-3 heart fit, and potential ruffs in both hands.  So to people in this camp, 1NT is wrong for another (critical) reason.

Going back to Alexander Woo's answer, hard agreeing with 1.  2♣ isn't forcing (although it can be much stronger than 1NT, say 16, 17).  You don't have enough to invite opposite their minimum; so show your "preference" (ignoring the 4=5 1♦ people here, for whom this is the fail case).  Partner with enough for game opposite two aces and a misfit will make a try, and you will accept.  Partner without enough for game will play 2♦ and hope to make it.  Better chance than in 2NT, at least.
I also agree that this hand shouldn't open (frankly, probably not even playing Precision).  Yes, opening is better than passing at winning the partscore, but 1♦, as discussed in your other question, is a limp squib (leaving open both majors at the 1 level, and a double for both they don't have if you pass), and having both minors means that the opponents have the majors and will find them - in which case, not only will you probably lose the partscore battle, the opponents will have better information about the shape in the play).  If not, then it's the misfit trap you see here.
Both majors 5=5, potentially with the ace in one of the suits, too, is why "rule of 20" was invented.  But this hand isn't that.
Re: cutaround, "spare", or otherwise pickup bridge.  Yes, you don't have the opportunity to deep-dive into partnership subtle agreements, but you have the benefit that you do have a decent idea how your many partners think, because you've played with everyone - as well as playing against them.  Take advantage of that!  You are keeping notes, yes? (not written down, necessarily, but maybe that's right for you!)  You are paying attention to the styles of your opponents, preparing for when it's your turn to play with them?  So you know, from experience, that there are "some in the club" that open light on shape (and maybe on the wrong suits or concentrations of values).  Is this partner one of them?  If they are, when they're your CHO, give them a little leeway, and don't bid as if they're in the solid, sound openers camp.  They know how to handle their shape calls better than you (from frequency, if nothing else) - if you let them.
Or, if you aren't willing to accept the results you get from "not hanging your partner", or can't (yet) analyze correctly opposite "they could be pushing too", it's time for you to clarify your style to partner instead, and ask them, no matter what they do with their regulars, not to set you up with these kinds of bids.  Do not say it's wrong, or bad, or anything else opinionish, but "I statements": "I'm sorry, I'm used to playing sound openers.  Could you do that for me this session, please?"

I don't understand your comment, "You don't have enough to invite opposite their minimum; s. I counted my hand as a good nine, almost 10 with two aces, a  J, and plenty of Ts, 9s, and 8s. I figured that we would  go down 1 at 2NT if partner had 12, make it if he had 14, and make 3NT if he had 16. Extrapolating, we might have gone down 2 if he had 10, except that he had a "bad" 10, with 60% of his points outside his two main suits.

Partner is say 11-16, and 5-4 in the minors at least (without 4 hearts.  Probably not 1=3=5=4.  Maybe not 2=2=5=4).  Yuck. 11 + 9 is 20, and you do not want to be in 2NT with a misfit 20.  Therefore, you do not have enough to invite. Really, you only want to "invite" when there are two categories, even if those are "minimum" and "extras".  Even in your comment, you've agreed there are 3 here.  So pass the buck to partner (showing a minimum without great fit) and be prepared to answer "good min or bad min" if they have the max.

The other issue is that because invites are designed around "minimum" and "extras", partner would, and should, have bid 3 on the hands that you are saying here "probably make 2".  Note: the biggest flaw in "standard" systems including 2/1, the thing that all the non-standard systems exist to solve, is the wide range of opener's rebids in auctions like this (or 1D-1H; 2D).  You just can't precisely deal with 11-17 (or 11-bad 16) opposite 6+ without some hands dropping through the cracks (too high or too low).  We do our best, but there will be some failures.

Oh, and: "plenty of Ts, 9s and 8s." Agree, and that's worth thinking about.  You have a good minimum (hence, "if they invite, accept").  But - I would trust that your minor 9s are pulling their weight; they will usually fill in partner's suits.  Your major intermediates, however, are worth less, without honours in partner's hand to "fill in" (or a fit, which you know you don't have). If partner has those honours with a minimum, then their own suits are weak - in which case, as you saw, your minor 9s don't full pull either.