text:
Does white really have a win in this pawn ending, as claimed by Tim Krabbé?
Update:     I emailed Tim Krabbé, and he agrees that  41. b4 bxa4  draws.

He has posted a PS about this just under his old analysis.

With respect to "Skawinski - Tomczak, European ch rapid, Warsaw 2011",

Tim Krabbé says that "White could have won with 41.b4!".

After  41. b4 bxa4 ,  they would have reached the position
[Title "The Position I'm Actually Interested In"]
[fen "8/8/2p5/p2k1ppp/pP1P5/3K1PPP/8/8 w - - 0 42"]

with white to move.  Stockfish believes that from the above position,

everything other than bxa5 loses outright for white, and that after bxa5, a3 probably

holds for black due to the counter-breakthrough on the kingside.    Tim Krabbé does

address that counter-breakthrough, but only for  41. ... axb4 ,  rather than  41. ... bxa4 .
Here's what I currently believe to be optimal play from the above diagram:
[Title "What I Currently Believe is Optimal Play From That Position"]
[fen "8/8/2p5/p2k1ppp/pP1P5/3K1PPP/8/8 w - - 0 42"]

1.bxa5 a3 2.Kc2 a2 3.Kb2 a1=Q+ 4.Kxa1 g4 5.hxg4 f4 6.gxf4 h4 7.a6 h3 8.a7 h2 9.a8=Q

Proof that white does not have a forced win after that line:

The main line continues 9. ... h1=Q+ 10.Kb2 Qg2+ 11.Kb3 Qxf3+ 12.Kb4 Qxf4 13.Qd8+ Ke4.  Playing Ka2 instead of Kb2 doesn't change anything.

If white's king goes back to rank 1 instead of to rank 3 or back to rank 2 instead of to

rank 4, then black checks horizontally from the f-file until white's king goes to rank 4.

Otherwise, black doesn't care how white's king goes from a1 to rank 4.
Let "6ptbd" be short for "6-piece tablebase draw-or-win-for-black".
If white's king goes to a4 instead of b4 then:

Black plays Qd1+.  If white plays Ka3 then black plays Qa1+.

If white doesn't play that or doesn't follow it up with Kb3 then Qxd4 followed by Qxf4

yields a 6ptbd, so for the next sentence, assume 12.Ka4 Qa1+ 13.Kb3 Qxa8.

If Kc3 then Qa1+ followed by Qxd4 yields a 6ptbd, else Kxd4 yields a 6ptbd.
Stephen comments that after Qxf4, the position is a finalgen table base draw.  Since I already

had a majority of the relevant analysis together before I read that, I'll give analysis which, without relying on finalgen (but still relying on 5&6-piece tablebases being correct about certain positions

not being forced wins for white), shows that white doesn't have a forced win after Qxf4.

After Qxf4, Qd8+ is the only move which doesn't let black immediately

capture on d4 for a 6ptbw.    After Ke4, the only moves for white which

don't let black immediately capture for a 6ptbd are  Kc3,Qd7,g5 .
After Ke4, if Kc3 then black gets at least a draw as follows:

Black starts with Qc1+, and then black's queen moves as far up as doesn't let white capture

it immediately while still checking from below unless white's king goes to c5 or rank 6.

If Kc5 then Qa3+.  Since b5 and and d3 and d5 are covered by black's pawn and king,

the only way out of those checks is going to rank 6, and the only ways for

white's king to get there are a5 and c5, which mean black's queen will be on a3.

In that case, Kxc6 is a 6ptbd, and if Kb6 then Qb4+ followed by Qxd4 is a tablebase draw.
After Ke4, if Qd7 then black gets at least a draw as follows:

Black starts with Qd2+.  If Kc4 or Kc5 then black mostly follows the procedure described in the previous paragraph, but if Qb4+ Ka6 then Qa4+ followed by Qxd4 rather than an immediate Qxd4, and if Qb4+ Kxc6 then it's already a 6ptbd which Qxd4 would lose.

Otherwise, Qxd4 gives a 6ptbd.
After Ke4, if g5 then black gets at least a draw as follows:

Until black can check from below in a way that's not Qb1 checking Kb4, black moves so that [white_king's_square,black_queen's_square] is an element of {[a1,d1],[b1,d1],[a2,d2],[b2,d2],[a3,c1],[b3,d1],[b4,d2]}.
Once black can check from below in a way that's not Qb1 checking Kb4, black then does so as close to white's king as doesn't let white capture it immediately, and continues that until white's king reaches rank 6.  If Kd6 then Qxd4+ is a 6ptbd.  The only other way out of the part of this paragraph that came before this sentence is Kb6.  Once white has played that, until white captures c6 or blocks a check or the rest of this sentence calls for Qxg5, black moves so that [white_king's_square,black_queen's_square] is an element of

{[a6,a4],[a7,a4],[a8,a4],[b6,b4],[b7,b5],[b8,b5],[c7,a5],[c8,f5],[d6,d5],[d7,d5],[e7,g5],[e8,g8]}.

White capturing c6 is a 6ptbd, and if white blocks a check then queen-takes-pawn is a 6ptbd.

The sentence two ago only calls for Qxg5 after Ke7, and in that case it's a 6ptbd.
Therefore, none of Kc3,Qd7,g5 keep a forced win for white.  QED

Thus, any forced win for white must deviate from that line before h1=Q+.

I analyzed the position with an engine and I came to the same conclusion. The line you give is more or less forced. I think you're right, the position is a draw.

I let FinalGen generate a tablebase for the final position in your second diagram (3Q4/8/2p5/8/1K1PkqP1/8/8/8 w - - 0 1) - it's a draw. (The pawn endgame in the first diagram is too complex for FinalGen.)

So, after a8=Q, there can't be a forced win for white.

@Tony Ennis: The tablebase I generated shows that the position is already a draw after 12...Qxf4, so 13.Qd8+ is not at fault.

@TonyEnnis:  I didn't explore that because 13.Qa5+ Kxd4 gives a 6-piece tablebase draw.

In your last position (the critical one), Black draws by perpetual check with ...Qd2+. Checked with the engine, but even decent human player can realize that. Lines are pretty straightforward in my opinion...

It seems you have solved it; you emailed Tim Krabbé and found a draw in the comments. If your question is answered, consider compiling the answer in an actual answer, instead of an update in the question. Right now it seems this question is unanswered.

I've looked at this question a lot since I first saw it.  I spent the last day of 2016 looking at its variations.  I wasn't able to find a variation with white winning.
SETUP:

GUI: Athena-3.5.1 build 2861
ENGINE: stockfish_16123114_x64_modern (daily build - none more recent)
ENGINE: komodo-10.1-64bit
ENGINE: andscacs-0.89
ENGINE: Fire_5_x64-popcnt

I always assigned white the strongest chess engine to give it advantage to win, and I used more resources (more memory and CPUs) to allowed for deeper analysis.
MAIN LINE:
The so-called 'main line' simply deteriorates into move repetition; so a draw.
This position ultimately appears unwinnable for white because black's act of advancing a pawn with 1 .. a4 draws white's King away from the centre with 2. Kc2 .. ultimately placing the King on a1 with 6. Kxa1 ...  Black exploits this positioning in a very clever way with another foot race white falsely appears to win.
Looking forward to having whites King capture the promoted a column black pawn, Black chooses to moves 2. .. g4 to sacrifice material and to open the h column. This material sacrifice 2. .. g4 ultimately allows the pawn on h file to race to promotion and gains black tempo by putting whites a1 King in check.  The sacrifice doesn't look it provides advantage yet because black has to wait for whites King to be put in check.  However black's material sacrifice on 2. .. g4 indeed gains tempo because of the positioning of white's King.
Recall, white's king has been drawn to a1.  The foot race between white's a5 pawn and black's soon-to-be h4 pawn seems to advantage white (who promotes first) except that black Pawn's promotion putting white's a1 King in check is where black realizes the tempo.  As long as black continues to check, white position is unwinnable. White's promoted Queen never gets a chance.

[Event "Ricky Demer's Position: Main Line"]
[Site "GHOST"]
[Date "2016.12.31"]
[Round "2"]
[White "Stockfish 16123114 x64 POPCNT"]
[Black "Stockfish 16123114 x64 POPCNT"]
[Result "*"]
[BlackElo "3397"]
[Time "13:29:29"]
[WhiteElo "3397"]
[TimeControl "300"]
[SetUp "1"]
[FEN "8/8/2p5/p2k1ppp/pP1P4/3K1PPP/8/8 w - - 0 1"]
[Termination "normal"]
[PlyCount "71"]
[WhiteType "human"]
[BlackType "human"]
[FEN "8/8/2p5/p2k1ppp/pP1P4/3K1PPP/8/8 w - - 0 1"]

1. bxa5 a3 2. Kc2 g4 3. hxg4 f4 4. gxf4 a2 5. Kb2 a1=Q+ 6. Kxa1 h4 7. a6 h3 8. a7 h2 9. a8=Q h1=Q+ 10. Ka2 Qg2+ 11. Ka1 Qh1+ 12. Ka2 Qg2+ 13. Ka1 Qf1+ 14. Ka2 Qe2+ 15. Ka1 Qe1+ 16. Ka2 Qf2+ 17. Ka1 Qf1+ 18. Ka2 Qf2+ 19. Ka1 Qxd4+ 20. Kb1 Qd1+ 21. Ka2 Qc2+ 22. Ka1 Qd1+ 23. Ka2 Qd2+ 24. Ka1 Qc1+  25. Ka2  Qc2+ 26. Ka1 Qc3+ 27. Kb1 {(Ka1-b1 Qc3-e1+ Kb1-c2 Qe1-f2+ Kc2-b1 Qf2-e1+) 0.00/42 4} Qe1+  28. Ka2  Qf2+  29. Ka1 Qe1+ 30. Ka2 Qf2+ 31. Ka1 Qg1+ 32. Ka2 Qg2+ 33. Ka1 Qf1+ 34. Ka2 Qe2+ 35. Ka1 Qe1+ 36. Ka2 (36. Ka2 {(Ka1-a2)
0.00/47 3-fold repetition}) *

FALSE HOPE:
The variation you suggest has white's King taking the pawn on a2 with 6. Kxa2 rather than allow it to promote and take it on a1.
The apparent advantage to white is illusory.  Because black appears to win the second race to pawn promotion 8. .. h1=Q, and because white's King is still on a2 white King's moves are nuanced, ultimately allowing black to take all white's Pawns (as white is taking black's pawns) leading to a stalemate (again) due to insufficient material.
The variation supposedly advantaging white, in fact allows black to take all of white's other pieces.  Here are some examples using Stockfish against Stockfish.

[Event "Ricky Demer's Position: White hope?"]
[Site "GHOST"]
[Date "2016.12.31"]
[Round "1"]
[White "Stockfish 16123114 x64 POPCNT"]
[Black "Stockfish 16123114 x64 POPCNT"]
[Result "*"]
[BlackElo "3210"]
[Time "13:05:02"]
[WhiteElo "3210"]
[TimeControl "40/2400:40/2400:40/2400"]
[SetUp "1"]
[Termination "insufficient material"]
[PlyCount "53"]
[WhiteType "program"]
[BlackType "program"]
[FEN "8/8/2p5/p2k1ppp/pP1P4/3K1PPP/8/8 w - - 0 1"]

1. bxa5 {(b4xa5 a4-a3 Kd3-c3 g5-g4 f3xg4 a3-a2 Kc3-b2 a2-a1B+ Kb2xa1 h5-h4
g3xh4 f5-f4 Ka1-a2 f4-f3 a5-a6 f3-f2 a6-a7 f2-f1Q a7-a8Q Qf1-f2+ Ka2-b3
Qf2-e3+ Kb3-c2 Qe3-e2+ Kc2-c3 Qe2-e3+ Kc3-b4 Qe3xd4+ Kb4-b3 Qd4-d3+ Kb3-b2
Qd3-d2+ Kb2-b1 Qd2-d3+ Kb1-c1 Qd3-e3+ Kc1-b2 Qe3-e2+ Kb2-b1 Qe2-f1+ Kb1-b2
Qf1-e2+) 0.00/30 11} a3 {(a4-a3 Kd3-c3 g5-g4 f3xg4 h5-h4 g3xh4 a3-a2 Kc3-b2
a2-a1Q+ Kb2xa1 f5-f4 a5-a6 f4-f3 a6-a7 f3-f2 a7-a8Q f2-f1Q+ Ka1-a2 Qf1-f2+
Ka2-b3 Qf2-e3+ Kb3-c2 Qe3-e2+ Kc2-c3 Qe2-e3+ Kc3-b4 Qe3xd4+ Kb4-b3 Qd4-d3+
Kb3-b2 Qd3-d2+ Kb2-b1 Qd2-d3+ Kb1-c1 Qd3-e3+ Kc1-b2 Qe3-e2+ Kb2-b1 Qe2-f1+
Kb1-b2 Qf1-e2+) 0.00/32 6} 2. Kc2 {(Kd3-c2 g5-g4 h3xg4 a3-a2 Kc2-b2 f5-f4
g3xf4 h5-h4 a5-a6 h4-h3 a6-a7 a2-a1R Kb2xa1 h3-h2 Ka1-a2 h2-h1Q a7-a8Q
Qh1-g2+ Ka2-a3 Qg2xf3+ Ka3-b4 Qf3xf4 Qa8-d8+ Kd5-e4 g4-g5 Qf4-d2+ Kb4-c5
Qd2-c3+ Kc5-b6 Qc3-b4+ Kb6xc6 Qb4-c4+ Kc6-b7 Qc4-b5+ Qd8-b6 Qb5xg5 Qb6-b1+
Ke4xd4 Qb1-b4+ Kd4-e3 Qb4-c3+ Ke3-e2) 0.00/29 9} g4 {(g5-g4 f3xg4 h5-h4
g3xh4 f5-f4 a5-a6 a3-a2 Kc2-b2 f4-f3 a6-a7 a2-a1R Kb2xa1 f3-f2 a7-a8Q
f2-f1Q+ Ka1-b2 Qf1-e2+ Kb2-c1 Qe2-f1+ Kc1-d2 Qf1-f2+ Kd2-d3 Qf2-f3+ Kd3-c2
Qf3-e2+ Kc2-b3 Qe2-c4+ Kb3-b2 Qc4-e2+) 0.00/31 5} 3. hxg4 {(h3xg4 a3-a2
Kc2-b2 f5-f4 g3xf4 h5-h4 a5-a6 h4-h3 a6-a7 a2-a1Q+ Kb2xa1 h3-h2 a7-a8Q
h2-h1Q+ Ka1-b2 Qh1-g2+ Kb2-b3 Qg2xf3+ Kb3-b4 Qf3xf4 Qa8-d8+ Kd5-e4 Kb4-c5
Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ d4-d5 Qf5-f2+ Kc5-c6 Qf2-c2+ Kc6-d7
Ke4xd5 Qd8-a5+ Kd5-e4 Qa5-b5 Ke4-f3 Qb5-d5+ Kf3-f4 Qd5-f7+ Kf4-e3 Qf7-e7+
Ke3-f4) 0.00/27 10} a2 {(a3-a2 Kc2-b2 f5-f4 g3xf4 h5-h4 a5-a6 h4-h3 a6-a7
a2-a1Q+ Kb2xa1 h3-h2 a7-a8Q h2-h1Q+ Ka1-b2 Qh1-g2+ Kb2-b3 Qg2xf3+ Kb3-b4
Qf3xf4 Qa8-d8+ Kd5-e4 Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ d4-d5
Qf5-f2+ Kc5-c6 Qf2-c2+ Kc6-d6 Qc2-h2+ Kd6-c5 Qh2-c2+ Kc5-b6 Qc2-b3+ Kb6-c5
Qb3-c3+ Kc5-d6 Qc3-e5+ Kd6-c6 Qe5-c3+ Kc6-d7 Qc3-h3+ Kd7-c7 Qh3-c3+ Kc7-d7)
0.00/31 6} 4. Kb2 {(Kc2-b2 f5-f4 g3xf4 h5-h4 a5-a6 h4-h3 a6-a7 a2-a1Q+
Kb2xa1 h3-h2 a7-a8Q h2-h1Q+ Ka1-b2 Qh1-g2+ Kb2-b3 Qg2xf3+ Kb3-b4 Qf3xf4
Qa8-d8+ Kd5-e4 Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ d4-d5 Qf5-f2+
Kc5-c6 Qf2-c2+ Kc6-b6 Qc2-b3+ Kb6-c5 Qb3-c3+ Kc5-d6 Qc3-e5+ Kd6-c6 Qe5-c3+
Kc6-d7 Qc3-h3+ Kd7-c7 Qh3-c3+ Kc7-d7) 0.00/33 9} f4 {(f5-f4 g3xf4 h5-h4
a5-a6 h4-h3 a6-a7 a2-a1Q+ Kb2xa1 h3-h2 a7-a8Q h2-h1Q+ Ka1-b2 Qh1-g2+ Kb2-b3
Qg2xf3+ Kb3-b4 Qf3xf4 Qa8-d8+ Kd5-e4 Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5
Qe6-f5+ d4-d5 Qf5-f2+ Kc5-c6 Qf2-c2+ Kc6-b6 Qc2-b3+ Kb6-c5 Qb3-c3+ Kc5-b5
Qc3-d3+ Kb5-c6 Qd3-c4+ Kc6-b7 Qc4-b5+ Kb7-a7 Qb5-c5+ Ka7-b7 Qc5-b5+)
0.00/33 4} 5. gxf4 {(g3xf4 h5-h4 a5-a6 h4-h3 a6-a7 a2-a1Q+ Kb2xa1 h3-h2
a7-a8Q h2-h1Q+ Ka1-b2 Qh1-g2+ Kb2-b3 Qg2xf3+ Kb3-b4 Qf3xf4 Qa8-d8+ Kd5-e4
Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ d4-d5 Qf5-f2+ Kc5-c6 Qf2-c2+
Kc6-b6 Qc2-b3+ Kb6-c5 Qb3-c3+ Kc5-b5 Qc3-d3+ Kb5-b4 Qd3-d4+ Kb4-a3 Qd4-c5+
Ka3-a4 Qc5-d4+ Ka4-a3) 0.00/34 10} h4 {(h5-h4 Kb2xa2 h4-h3 a5-a6 h3-h2
a6-a7 h2-h1Q a7-a8Q Qh1-g2+ Ka2-b3 Qg2xf3+ Kb3-b4 Qf3xf4 Qa8-d8+ Kd5-e4
Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ d4-d5 Qf5-f2+ Kc5-c6 Qf2-c2+
Kc6-b6 Qc2-b3+ Kb6-c5 Qb3-c3+ Kc5-b5 Qc3-d3+ Kb5-c6 Qd3-c4+ Kc6-b6 Qc4-b4+
Kb6-c6 Qb4-c4+) 0.00/31 5} 6. Kxa2 {(Kb2xa2 h4-h3 a5-a6 h3-h2 a6-a7 h2-h1Q
a7-a8Q Qh1-g2+ Ka2-b3 Qg2xf3+ Kb3-b4 Qf3xf4 Qa8-d8+ Kd5-e4 Kb4-c5 Qf4xg4
Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ d4-d5 Qf5-f2+ Kc5-c6 Qf2-c2+ Kc6-b6 Qc2-b3+
Kb6-c5 Qb3-c3+ Kc5-b5 Qc3-d3+ Kb5-b4 Qd3-d4+ Kb4-a3 Qd4-c5+ Ka3-a4 Qc5-d4+
Ka4-a3) 0.00/31 6} h3 {(h4-h3 a5-a6 h3-h2 a6-a7 h2-h1Q a7-a8Q Qh1-g2+
Ka2-b3 Qg2xf3+ Kb3-b4 Qf3xf4 Qa8-d8+ Kd5-e4 Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+
Kc6-c5 Qe6-f5+ d4-d5 Qf5-f2+ Kc5-c6 Qf2-c2+ Kc6-b6 Qc2-b3+ Kb6-c5 Qb3-c3+
Kc5-b5 Qc3-d3+ Kb5-b4 Qd3-d4+ Kb4-a3 Qd4-c3+ Ka3-a4 Qc3-d4+ Ka4-a3) 0.00/32
6} 7. a6 {(a5-a6 h3-h2 a6-a7 h2-h1Q a7-a8Q Qh1-g2+ Ka2-b3 Qg2xf3+ Kb3-b4
Qf3xf4 Qa8-d8+ Kd5-e4 Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ d4-d5
Qf5-f2+ Kc5-c6 Qf2-c2+ Kc6-b6 Qc2-b3+ Kb6-c5 Qb3-c3+ Kc5-d6 Qc3-e5+ Kd6-c6
Qe5-c3+ Kc6-d7 Ke4xd5 Kd7-e8+ Kd5-e4 Qd8-h4+ Ke4-d5 Qh4-d8+) 0.00/33 10} h2
{(h3-h2 a6-a7 h2-h1Q a7-a8Q Qh1-g2+ Ka2-b3 Qg2xf3+ Kb3-b4 Qf3xf4 Qa8-d8+
Kd5-e4 Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ Kc5-c4 Qf5-e6+ d4-d5
Qe6-a6+ Kc4-c5 Qa6-a3+ Kc5-c6 Qa3-a4+ Kc6-d6 Qa4-a3+ Kd6-e6 Qa3-h3+ Ke6-d6
Qh3-h2+ Kd6-c5 Qh2-c2+ Kc5-b6 Qc2-b3+ Kb6-c5 Qb3-c3+ Kc5-b5 Qc3-d3+ Kb5-b4
Qd3-d4+ Kb4-b5 Qd4-b2+ Kb5-c6 Qb2-c3+ Kc6-b5) 0.00/34 7} 8. a7 {(a6-a7
h2-h1Q a7-a8Q Qh1-g2+ Ka2-b3 Qg2xf3+ Kb3-b4 Qf3xf4 Qa8-d8+ Kd5-e4 Kb4-c5
Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ Kc5-c4 Qf5-e6+ d4-d5 Qe6-a6+ Kc4-c5
Qa6-a3+ Kc5-c6 Qa3-a4+ Kc6-d6 Qa4-a3+ Kd6-e6 Qa3-h3+ Ke6-d6 Qh3-h2+ Kd6-c5
Qh2-c2+ Kc5-b6 Qc2-b3+ Kb6-c5 Qb3-c3+ Kc5-b5 Qc3-b2+ Kb5-c6 Qb2-c3+ Kc6-b5)
0.00/35 20} h1=Q {(h2-h1Q a7-a8Q Qh1-g2+ Ka2-b3 Qg2xf3+ Kb3-b4 Qf3xf4
Qa8-d8+ Kd5-e4 Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ Kc5-c4 Qf5-e6+
d4-d5 Qe6-a6+ Kc4-c5 Qa6-a3+ Kc5-c6 Qa3-a4+ Kc6-d6 Qa4-a3+ Kd6-e6 Qa3-h3+
Ke6-d6 Qh3-h2+ Kd6-c5 Qh2-c2+ Kc5-b6 Qc2-b3+ Kb6-c5 Qb3-c3+ Kc5-b5 Qc3-b2+
Kb5-c6 Qb2-c3+ Kc6-b5) 0.00/35 4} 9. a8=Q {(a7-a8Q Qh1-g2+ Ka2-b3 Qg2xf3+
Kb3-b4 Qf3xf4 Qa8-d8+ Kd5-e4 Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+
Kc5-c4 Qf5-e6+ d4-d5 Qe6-a6+ Kc4-c5 Qa6-a3+ Kc5-c6 Qa3-a4+ Kc6-d6 Qa4-a3+
Kd6-e6 Qa3-h3+ Ke6-d6 Qh3-h2+ Kd6-c5 Qh2-c2+ Kc5-b6 Qc2-b3+ Kb6-c5 Qb3-c3+
Kc5-b5 Qc3-b2+ Kb5-c6 Qb2-c3+ Kc6-b5) 0.00/35 3} Qg2+ {(Qh1-g2+ Ka2-a1
Qg2-g1+ Ka1-b2 Qg1-f2+ Kb2-b3 Qf2xf3+ Kb3-b4 Qf3xf4 Qa8-d8+ Kd5-e4 Kb4-c5
Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ Kc5-c4 Qf5-e6+ d4-d5 Qe6-a6+ Kc4-c5
Qa6-a3+ Kc5-c6 Qa3-a4+ Kc6-d6 Qa4-a3+ Kd6-e6 Qa3-h3+ Ke6-d6 Qh3-h2+ Kd6-c5
Qh2-c2+ Kc5-b6 Qc2-b3+ Kb6-c5 Qb3-c3+ Kc5-b5 Qc3-b2+ Kb5-c6 Qb2-c3+ Kc6-b5)
0.00/35 12} 10. Ka1 {(Ka2-a1 Qg2-f1+ Ka1-b2 Qf1-f2+ Kb2-b3 Qf2xf3+ Kb3-b4
Qf3xf4 Qa8-d8+ Kd5-e4 Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ Kc5-c4
Qf5-e6+ d4-d5 Qe6-a6+ Kc4-c5 Qa6-a3+ Kc5-c6 Qa3-a4+ Kc6-d6 Qa4-a3+ Kd6-e6
Qa3-h3+ Ke6-d6 Qh3-h2+ Kd6-c5 Qh2-c2+ Kc5-b6 Qc2-b3+ Kb6-c5 Qb3-c3+ Kc5-b5
Qc3-b2+ Kb5-c6 Qb2-c3+ Kc6-b5) 0.00/36 8} Qf1+ {(Qg2-f1+ Ka1-a2 Qf1-e2+
Ka2-a1 Qe2-d1+ Ka1-b2 Qd1-d2+ Kb2-a1 Qd2-d1+) 0.00/37 19} 11. Ka2 {(Ka1-a2
Qf1-e2+ Ka2-a1 Qe2-d1+ Ka1-b2 Qd1-d2+ Kb2-a1 Qd2-d1+) 0.00/38 8} Qg2+
{(Qf1-g2+) 0.00/42 26} 12. Kb3 {(Ka2-b3 Qg2xf3+ Kb3-b4 Qf3xf4 Qa8-d8+
Kd5-e4 Kb4-c5 Qf4xg4 Kc5xc6 Qg4-e6+ Kc6-c5 Qe6-f5+ Kc5-c4 Qf5-e6+ d4-d5
Qe6-a6+ Kc4-c5 Qa6-a3+ Kc5-c6 Qa3-a4+ Kc6-d6 Qa4-a3+ Kd6-e6 Qa3-h3+ Ke6-d6
Qh3-h2+ Kd6-c5 Qh2-c2+ Kc5-b6 Qc2-b3+ Kb6-c5 Qb3-c3+ Kc5-b5 Qc3-b2+ Kb5-c6
Qb2-c3+ Kc6-b5) 0.00/35 26 Black forfeits on time} Qxf3+ {(Qg2xf3+ Kb3-b4
Qf3xf4 Qa8-d8+ Kd5-e4 g4-g5 Qf4-d2+ Kb4-c5 Qd2-c3+ Kc5-b6 Qc3-b4+ Kb6-a7
Qb4-a4+ Ka7-b8 Qa4-b5+ Kb8-c8 Qb5-f5+ Kc8-b7 Qf5-b5+ Kb7-c7 Qb5-a5+ Kc7-c8
Qa5-f5+) 0.00/35 123} 13. Ka2 {(Kb3-a2 Qf3xf4 Qa8-a5+ Kd5-e4 Qa5-c5 Qf4-d2+
Ka2-b3 Qd2-d3+ Kb3-a2 Qd3xd4 Qc5xc6+ Qd4-d5+ Qc6xd5+ Ke4xd5 g4-g5 Kd5-e5
Ka2-b3 Ke5-f5 g5-g6 Kf5-f6 g6-g7 Kf6xg7 Kb3-c4 Kg7-f6 Kc4-d4 Kf6-g5 Kd4-e4
Kg5-g4 Ke4-d3 Kg4-h3 Kd3-d4 Kh3-g2 Kd4-c3 Kg2-f1 Kc3-b2 Kf1-e2 Kb2-c2
Ke2-e3 Kc2-c3 Ke3-f4 Kc3-c2 Kf4-g5 Kc2-d3 Kg5-g6 Kd3-c3 Kg6-g5) 0.00/39
234} Qxf4 {(Qf3xf4 Qa8-d8+ Kd5-c4 Qd8-b6 Qf4-d2+ Ka2-a3 Qd2-c1+ Ka3-a2
Qc1-c2+ Ka2-a3 Qc2-c3+ Ka3-a2 Qc3-d2+) 0.00/42 278} 14. Qa5+ {(Qa8-a5+
Kd5-e4 Qa5-c5 Qf4-d2+ Ka2-b3 Qd2-d3+ Kb3-a2 Qd3xd4 Qc5xc6+ Qd4-d5+ Qc6xd5+
Ke4xd5 g4-g5 Kd5-e5 g5-g6 Ke5-f6 Ka2-b3 Kf6-g7 Kb3-c4 Kg7-f8 Kc4-d5 Kf8-g7
Kd5-c5 Kg7-f6 Kc5-d5 Kf6-g7) 0.00/41 247} Kxd4 {(Kd5xd4 Qa5-b4+ Kd4-e5
Qb4-c5+ Ke5-f6 g4-g5+ Kf6-g6 Qc5xc6+ Kg6-f7 Ka2-b1 Qf4xg5 Qc6-c4+ Kf7-f6
Qc4-a6+ Kf6-g7 Qa6-b7+ Kg7-f6 Qb7-a6+) 0.00/43 354} 15. Kb2 {(Ka2-b2 Qf4-e3
Qa5-a4+ Kd4-d5 Kb2-c2 Kd5-d6 Qa4-b4+ Kd6-d5 g4-g5 Qe3-e2+ Kc2-c3 Qe2-d1
Qb4-f4 Qd1-e1+ Kc3-d3 Qe1-d1+ Kd3-c3) 0.00/36 67} Ke4 {(Kd4-e4 Qa5-a4+
Ke4-e3 Qa4xc6 Qf4-d4+ Kb2-b3 Qd4-d1+ Kb3-a3 Qd1-d3+ Ka3-a4 Qd3-d4+ Ka4-b5
Ke3-f4 Kb5-a5 Qd4-e5+ Ka5-b4 Qe5-e4+ Qc6xe4+ Kf4xe4 Kb4-b5 Ke4-f4 Kb5-c5
Kf4xg4 Kc5-d4 Kg4-g5 Kd4-c4 Kg5-h4 Kc4-c3 Kh4-g5 Kc3-c4) 0.00/35 52} 16.
Qc3 {(Qa5-c3 Ke4-d5 Qc3-a5+ Kd5-e6 g4-g5 Qf4-d4+ Kb2-b3 c6-c5 Qa5-c3 Qd4-e4
Qc3xc5 Qe4-e5 Qc5-b6+ Ke6-f7 Qb6-f2+ Kf7-g6 Qf2-f3 Qe5-e6+ Kb3-b4 Kg6xg5
Kb4-c3 Kg5-g6 Qf3-g3+ Kg6-f7 Qg3-f4+ Kf7-g6 Kc3-d2 Qe6-d5+ Kd2-c3 Qd5-c5+
Kc3-b2 Qc5-d5 Qf4-g3+ Kg6-f7 Qg3-f4+ Kf7-g6) 0.00/36 43} Kd5 {(Ke4-d5
Qc3-d3+ Qf4-d4+ Kb2-c2 Qd4xd3+ Kc2xd3 Kd5-e5 g4-g5 Ke5-f5 g5-g6 Kf5xg6
Kd3-d4 Kg6-f5 Kd4-c5 Kf5-e4 Kc5-c4 c6-c5 Kc4-c3 Ke4-d5 Kc3-d3 c5-c4+ Kd3-c3
Kd5-c5 Kc3-c2 Kc5-d4 Kc2-d2 c4-c3+ Kd2-c2 Kd4-e5 Kc2-d1 Ke5-f6 Kd1-c2
Kf6-g6 Kc2-d1 c3-c2+ Kd1-c1 Kg6-f6 Kc1xc2 Kf6-g7 Kc2-c3 Kg7-g6 Kc3-c4
Kg6-g5 Kc4-c3 Kg5-h4 Kc3-d4 Kh4-g5 Kd4-c3) 0.00/46 64} 17. Qd3+ {(Qc3-d3+
Qf4-d4+ Kb2-c2 Qd4xd3+ Kc2xd3 Kd5-e5 g4-g5 Ke5-f5 g5-g6 Kf5xg6 Kd3-d4
Kg6-f5 Kd4-c5 Kf5-e4 Kc5-c4 c6-c5 Kc4-c3 Ke4-d5 Kc3-d3 c5-c4+ Kd3-c3 Kd5-c5
Kc3-c2 Kc5-d4 Kc2-d2 c4-c3+ Kd2-c1 Kd4-d3 Kc1-d1 c3-c2+ Kd1-c1 Kd3-e3
Kc1xc2 Ke3-e4 Kc2-c3 Ke4-e3 Kc3-c2) 0.00/48 56} Qd4+ {(Qf4-d4+ Kb2-c2
Qd4xd3+ Kc2xd3 Kd5-e5 g4-g5 Ke5-f5 g5-g6 Kf5xg6 Kd3-d4 Kg6-f5 Kd4-c5 Kf5-e4
Kc5-c4 c6-c5 Kc4-c3 Ke4-d5 Kc3-d3 c5-c4+ Kd3-c2 Kd5-d4 Kc2-d2 c4-c3+ Kd2-c2
Kd4-e4 Kc2xc3 Ke4-e3 Kc3-c2 Ke3-f4 Kc2-d2 Kf4-f3 Kd2-d3 Kf3-f2 Kd3-d2
Kf2-f3) 0.00/51 72} 18. Kc2 {(Kb2-c2 Qd4xd3+ Kc2xd3 Kd5-e5 g4-g5 Ke5-f5
g5-g6 Kf5xg6 Kd3-d4 Kg6-f5 Kd4-c5 Kf5-e4 Kc5-c4 c6-c5 Kc4-c3 Ke4-d5 Kc3-d3
c5-c4+ Kd3-c2 Kd5-d4 Kc2-d2 c4-c3+ Kd2-c2 Kd4-e4 Kc2xc3 Ke4-e3 Kc3-c2
Ke3-e4 Kc2-c3) 0.00/55 55} Qxd3+ {(Qd4xd3+ Kc2xd3 Kd5-e5 g4-g5 Ke5-f5 g5-g6
Kf5xg6 Kd3-d4 Kg6-f5 Kd4-c5 Kf5-e4 Kc5-c4 c6-c5 Kc4-c3 Ke4-d5 Kc3-d3 c5-c4+
Kd3-c3 Kd5-c5 Kc3-b2 Kc5-d4 Kb2-c2 c4-c3 Kc2-c1 Kd4-d3 Kc1-d1 c3-c2+ Kd1-c1
Kd3-e3 Kc1xc2 Ke3-e2 Kc2-c1 Ke2-f2 Kc1-d2 Kf2-g3 Kd2-c3 Kg3-h2 Kc3-d2
Kh2-g3) 0.00/57 47} 19. Kxd3 {(Kc2xd3 Kd5-e5 g4-g5 Ke5-f5 g5-g6 Kf5xg6
Kd3-d4 Kg6-f5 Kd4-c5 Kf5-e4 Kc5-c4 c6-c5 Kc4-c3 Ke4-d5 Kc3-d3 c5-c4+ Kd3-c3
Kd5-c5 Kc3-b2 Kc5-d4 Kb2-c2 c4-c3 Kc2-c1 Kd4-d3 Kc1-d1 c3-c2+ Kd1-c1
Kd3-c3) 0.00/56 54} Ke5 {(Kd5-e5 g4-g5 Ke5-f5 g5-g6 Kf5xg6 Kd3-d4 Kg6-f5
Kd4-c5 Kf5-e4 Kc5-c4 c6-c5 Kc4-c3 Ke4-d5 Kc3-d3 c5-c4+ Kd3-c3 Kd5-c5 Kc3-b2
Kc5-d4 Kb2-c2 c4-c3 Kc2-c1 Kd4-d3 Kc1-d1 c3-c2+ Kd1-c1 Kd3-c3) 0.00/56 52}
20. g5 {(g4-g5 Ke5-f5 g5-g6 Kf5xg6 Kd3-d4 Kg6-f5 Kd4-c5 Kf5-e4 Kc5-c4 c6-c5
Kc4-c3 Ke4-d5 Kc3-d3 c5-c4+ Kd3-c3 Kd5-c5 Kc3-b2 Kc5-d4 Kb2-c2 c4-c3 Kc2-c1
Kd4-d3 Kc1-d1 c3-c2+ Kd1-c1 Kd3-c3) 0.00/55 56} Kf5 {(Ke5-f5 g5-g6 Kf5xg6
Kd3-d4 Kg6-f5 Kd4-c5 Kf5-e4 Kc5-c4 c6-c5 Kc4-c3 Ke4-d5 Kc3-d3 c5-c4+ Kd3-c3
Kd5-c5 Kc3-b2 Kc5-d4 Kb2-c2 c4-c3 Kc2-c1 Kd4-d3 Kc1-d1 c3-c2+ Kd1-c1
Kd3-c3) 0.00/53 48} 21. g6 {(g5-g6 Kf5xg6 Kd3-d4 Kg6-f5 Kd4-c5 Kf5-e4
Kc5-c4 c6-c5 Kc4-c3 Ke4-d5 Kc3-d3 c5-c4+ Kd3-c3 Kd5-c5 Kc3-b2 Kc5-d4 Kb2-c2
c4-c3 Kc2-c1 Kd4-d3 Kc1-d1 c3-c2+ Kd1-c1 Kd3-c3) 0.00/54 70} Kxg6 {(Kf5xg6
Kd3-c2 Kg6-f6 Kc2-d3 Kf6-e5 Kd3-e3 c6-c5 Ke3-d3 Ke5-d5 Kd3-c3 Kd5-e4 Kc3-c4
Ke4-e3 Kc4xc5 Ke3-f2 Kc5-c4 Kf2-g1 Kc4-c3 Kg1-f2 Kc3-c4) 0.00/50 49} 22.
Kc2 {(Kd3-c2 c6-c5 Kc2-d3 Kg6-f5 Kd3-c4 Kf5-e4 Kc4-c3 Ke4-d5 Kc3-d3 c5-c4+
Kd3-c3 Kd5-c5 Kc3-b2 Kc5-d4 Kb2-c2 c4-c3 Kc2-c1 Kd4-d3 Kc1-d1 c3-c2+ Kd1-c1
Kd3-c3) 0.00/82 54} c5 {(c6-c5 Kc2-b1 Kg6-f5 Kb1-c2 Kf5-e4 Kc2-c3 Ke4-d5
Kc3-d3 c5-c4+ Kd3-c3 Kd5-c5 Kc3-b2 Kc5-d4 Kb2-c2 c4-c3 Kc2-c1 Kd4-d3 Kc1-d1
c3-c2+ Kd1-c1 Kd3-c3) 0.00/108 48} 23. Kb1 {(Kc2-b1 c5-c4 Kb1-c2 Kg6-f7
Kc2-c3 Kf7-e6 Kc3-b2 Ke6-e5 Kb2-c3 Ke5-d5 Kc3-b2 Kd5-d4 Kb2-c2 c4-c3 Kc2-c1
Kd4-d3 Kc1-d1 c3-c2+ Kd1-c1 Kd3-c3) 0.00/125 59} c4 {(c5-c4 Kb1-c2 Kg6-f7
Kc2-c3 Kf7-e6 Kc3-b2 Ke6-e5 Kb2-c3 Ke5-d5 Kc3-b2 Kd5-d4 Kb2-c2 c4-c3 Kc2-c1
Kd4-d3 Kc1-d1 c3-c2+ Kd1-c1 Kd3-c3) 0.00/127 7} 24. Kb2 {(Kb1-b2 Kg6-f7
Kb2-c3 Kf7-e6 Kc3-b2 Ke6-e5 Kb2-c3 Ke5-d5 Kc3-b2 Kd5-d4 Kb2-c2 c4-c3 Kc2-c1
Kd4-d3 Kc1-d1 c3-c2+ Kd1-c1 Kd3-c3) 0.00/127 26} Kh5 {(Kg6-h5 Kb2-c3 Kh5-g5
Kc3-c2 c4-c3 Kc2-b1 Kg5-g6 Kb1-c2 Kg6-g7 Kc2xc3 Kg7-g6 Kc3-b2 Kg6-g7
Kb2-c3) 0.00/127 3} 25. Ka1 {(Kb2-a1 c4-c3 Ka1-b1 Kh5-g6 Kb1-c2 Kg6-g7
Kc2xc3 Kg7-g6 Kc3-b2 Kg6-g7 Kb2-c3) 0.00/127 6} c3 {(c4-c3 Ka1-b1 Kh5-g6
Kb1-c2 Kg6-g7 Kc2xc3 Kg7-g6 Kc3-c4 Kg6-g5 Kc4-d3 Kg5-f6 Kd3-c4 Kf6-g5)
0.00/127} 26. Kb1 {(Ka1-b1 c3-c2+ Kb1xc2 Kh5-g6 Kc2-b3 Kg6-f6 Kb3-c4 Kf6-e6
Kc4-c5 Ke6-f6 Kc5-b6 Kf6-g7 Kb6-c5 Kg7-f6) 0.00/127} c2+ {(c3-c2+ Kb1xc2
Kh5-g6 Kc2-b3 Kg6-f6 Kb3-c4 Kf6-e6 Kc4-c5 Ke6-f6 Kc5-b6 Kf6-g7 Kb6-c5
Kg7-f6) 0.00/127} 27. Kxc2 {(Kb1xc2 Kh5-g6 Kc2-b3 Kg6-f6 Kb3-c4 Kf6-e6
Kc4-c5 Ke6-f6 Kc5-c4) 0.00/127 1 Insufficient material} *

QUESTION: Does white really have a win in this pawn ending, as claimed by Tim Krabbé?

ANSWER: With respect to Tim Krabbé, if the strongest chess engines in the world cannot find a winning line for White, it's reasonable to infer there isn't one.

This is an old answer, but Stockfish still cannot find the winning line in some cases where humans can.

Feel free to find it.

I'm not implying anything about your claim about this particular pawn ending. I commented only about your final statement that relies on "the strongest chess engines in the world", which is not a very good argument as can be seen from the examples in the linked post. That's all. =)

It's true that there may be blind-spots in 'a chess engine'.  There are far bigger blindspots in human chess thinking.  So while your comment may be factually correct, it is not helpful.

This position is won for black. A king can't stop stop two connected passed pawns.
I don't know who Tim Krabbé is but any beginner should be able to see this a won position for black in about 30 seconds. Even if white creates a passed pawn on the kingside, he can't stop black's connected passed pawns and black has tempo moves.
At the very least white might be able to draw but anyone who claims this is winning for white has no idea what they're talking about. If I'm wrong show me the analysis.

You seem to be confused about whose move it is in the diagram?


text:
Could I have some analysis by a player >2000 FIDE on this game?
I recently played in a chess tournament and the only game I lost was an extremely tricky battle between myself (USCF 1770ish) and this other guy (USCF 2000ish):
[Event "Bernardo Smith Amateur"]
[Site "Mechanics Institute Chess Club"]
[Date "2015.08.15"]
[Round "2"]
[White "Aaron T (1765)"]
[Black "Other Guy (2031)"]
[Result "0-1"]
[ECO ""]
[PlyCount "106"]
[FEN ""]

1. Nf3 d5 2. d4 Nf6 3. Bf4 g6 4. Nbd2 Bg7 5. e3 a6 6. c4 O-O 7. Rc1 Re8 8. Bd3 Nc6 9. O-O Nh5 10. cxd5 Nxf4 exf4 Qxd5 Be4 Qd6 Bxc6 bxc6 Nb3 Be6 Nc5 Bd5 Ne5 f6 Ned3 Reb8 b3 a5 a4 Rb6 Re1 Rab8 Rb1 Bf7 Qf3 Bxb3 Qe3 Bd5 Rbc1 Kf7 Qd2 Ra8 Re2 Rbb8 Rce1 Re8 Rb1 Bh6 Rbe1 e6 g3 Bg7 Qc3 h5 Re3 h4 R1e2 Bh6 Qe1 hxg3 fxg3 Bc4 Qc3 Bd5 Qe1 Ra7 Rf2 Bg7 Ne5+ Kg8 Nxg6 Raa8 Nh4 Kf7 Qe2 Rh8 Nf3 Rab8 Ne5+ Kg8 Ned3 Rb1+ Rf1 Rxf1 Qxf1 Bc4 Qa1 Rh5 Qc3 Bxd3 Qxd3 Rd5 Rxe6 Qxc5 0-1

A few things to note about the game:

All pawn sacrifices I believed had compensation with different positional moves. I won't state the exact positional counterplay because I want to see what type of moves you come up with.

I missed Bxc7 early on

Around move 40 I was down to 6 minutes, explaining my blunder on move 51.

So my question is this:
I have been wanting a strong player to analyze my game for quite some time now, but all do not have the time to look over it with me. So I would like a SE member >2000 FIDE to analyze it for me.

All commentary is helpful, so say something if you believe it relevant, but it would be preferable to be >2000.

how much time did you start with?

@CognisMantis 60/ d5 sorry didn't say that

I'm FIDE rated 2125.
So for your game, yes 10.Bxc7 would have been good for white.
As far as the opening goes, usually Nd2 happens with pawn c3 instead pawn c4.  If you want to do pawn c4 then the knight goes to c3 to put more pressure on d5.
Also, I would not play pawn to a4 like you did in the game.  It only causes b3 to be weak in my opinion.
But even though you eventually lose the pawn on b3, the position is tough to crack for black since there are no good pawn breaks to open the position for the bishops and the white knights have good outpost squares.
Overall, good effort!

I don't understand 10.Bxc7 - why is this good?

@corsiKa Presumably 10. Bxc7 Qxc7?! 11. cxd5 and the Nc6 is pinned, so White gets the piece back a pawn up.

As a FM 2300 a few quick notes.
As noted Bxc7 was very strong.
Otherwise I really do not like 19. a4?
There was no need to weaken both b3 and b4 as your knight on c5 was doing a splendid job of keeping a4 under control.
Without a4 pawn, you have 4 potential black targets , a5, c6, c7 and e7 (plus potential penetriation via e6) vs your only weak d4 pawn. With a4 you are giving your OP b3 to attack which he does.
Otherwise, you did a reasonable job of playing your 2 knights vs his two bishops.
Even at the end it was not so terrible if not for your blunder.

source: Stack Exchange

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text:
On how to learn Xiangqi (Chinese Chess) or Shogi (Japanese Chess)
I learned international chess using the tutorials in Ubisoft's Chessmaster, alongside doing tactical and strategical exercises from books, studying master games, and from playing.
I want to learn how to play Xiangqi or Shogi. What resources would you recommend? I am particularly interested in software like Ubisoft's Chessmaster, i.e. interactive tutorials with the ability to play against a range of computer players at different levels.
P.S. I'm based in the UK, where there aren't any relevant clubs nearby, and English language resources are a must

I learned shogi from this book. http://www.amazon.com/Shogi-Beginners-John-Fairbairn/dp/4871872017/ref=sr_1_1?s=books&ie=UTF8&qid=1446638715&sr=1-1&keywords=shogi+for+beginners
snippet:  http://www.bromsgrove-abstract-games.org.uk/shogi.pdf
I bought a shogi set from The Shogi Association (A UK group). The fellow running it at the time (George Hodges) has since passed, I believe.
I also was fortunate to have a friend in Japan. He brought me back a Japanese language puzzle book. I don't recall the exact name, but they are mate-in-x puzzles where one must use all the pieces in hand.  Maybe they are called tsume puzzles? I saw the name referenced on that Amazon link.
It's a great game!

I have got that book as well, though I never progressed to a level were I could play a decent game. There is a certain shortage of books on shogi (or, I guess XiangQi), but this one is quite good.

@BlindKungFuMaster The best XiangQi books are in Chinese.

Yes, of course. I meant shogi/xiangqi books in English.

I learned Shogi from these videos.  It goes from absolute beginner to analysis of grand-master games.

I thought to myself "Is this HIDETCHI?" before clicking the link. I love that guy!

Try below Ebook, all free for download.
http://xiangqielephantgame.blogspot.my/p/download-free-ebook.html?m=1

Welcome to Chess SE! From your username, this seems to be a link to your site. Can you please edit your answer to state this clearly? Otherwise, your post can be perceived as spam.

There aren't any english resources for learning xiangqi other than the webpage mentioned above. There is a Malaysian titled player who produced xiangqi content in English. The link for his video resources on xiangqi can be found here: Link
There are a few xiangqi players on the pychess.org site's discord who are willing to help out in xiangqi studies and openings. But overall the game is less popular outside China.

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text:
Opening creation-is it ever possible?
I have invented (to the best of my knowledge) a really decent opening. I would like to note that over the ICC I have actually beaten a few masters with this opening, with one master having an ICC rating of 2400 (45 45). I would like to popularize my opening without somebody else stealing it from me, but I really don't know how. Is there a way to do this type of thing?

Side note: I will not actually say the opening

Can you clarify what you mean by "stealing it from me"?

@dfan NP, Lets say I play it against someone, and then that person creates a lecture about it or something like that.

No, you cannot prevent that.

You might be right, but lets see if anyone has any ideas

It might be a bit hard, and will come down mostly to luck, unless you can play it successfully in a major tournament. Many of the openings named after people, are due to large historical significance. Najdorf was not necessarily the first player to play the Najdorf Sicilian, but he managed to get his name attributed to it for other reasons.
Not sure if chess openings are the kinds of things you can copyright.

What about posting the opening here, or somewhere else, so that no matter what, you could always point to it and say that you made it first. It will be impossible to get into a major tournament and win with the spotlight, unless you're very good.

Publish in a chess magazine your analysis of the opening. But you have to understand that it is very difficult to discover a TN (theoretical novelty) - a single new move in a known line. Even harder is discovering a sound yet unknown opening.

@TonyEnnis I checked in three different Chess Databases, each containing zero games.

Did you show your cash at the 2400+ master in the opening?

@StudentT what do you mean?

Openings cannot be copyrighted, but analysis and comments can be.
The best you can do is probably to publish an extensive analysis of the variation online (or in a magazine, but you should make sure it is available online as well). In that article you should explicitly name the variation. You might also want to throw in some engine-engine games, instead of just concentrating on your own games. Real tournament games would probably be more convincing than online games as well.
If you do that you can always prove precedence by pointing out your article if somebody tries to reinvent and rename the variation. If the article is well written and contains high-level games, it is also quite likely that other people interested in the variation will quote/link you, i.e. accept and cement your precedence.

Just to point out that opening names can include trademarks, e.g. the Nescafe Frappe attack: 1. d4 Nf6 2. c4 c5 3. d5 b5 4. cxb5 a6 5. Nc3 axb5 6. e4 b4 7. Nb5 d6 8. Bc4

I suggest you to read the story of the invention of the Kingston Defence by Gavin Wilson. Based on this story I would advise you the following actions:

Be sure to triple check your opening hasn't got a name yet. See here. You never know, it could appear in some obscure publication you don't know about...
Work on your opening until you are sure you have analysed all the main responses for white and for black. Better testing it with your computer than against real players at this stage, to diminish the probability of it being "stolen".
Find a good name for your opening.
Publish your opening, as suggested by BlindKungFuMaster. A book, an article in a chess magazine, an online video... that's up to you.
Get some publicity for your opening/publication. See if you can find someone to make a review/comment on your publication. And be sure to play it.


text:
The Art of the Checkmate, Quiz 24: Is there a win?
This is quiz 24 from The Art of the Checkmate by Renaud & Kahn.
Black to play and win
rn3rk1/pp3ppp/3b1n2/2pPq3/2B1P3/1NN2bP1/PPPQ1P1P/R1B2RK1 b - - 0 1

The authors give this as the winning line:

 1... Qh5 2. Be2 (as Black was threatening Qh3-g2#) Ng4 (threatening mate on h2) 3. h4 Qxh4 4. gxh4 Bh2#

However, I think White has a simple refutation:

 2. Re1 prepares Bf1, stopping the Qh3-g2 threat, and Ng4 threats can be nullified with h4, as the Queen sacrifice doesn't work now as the King has a flight square

So, my questions are:

Is there a forced win (mate or material)?
If so, what is it?
If not, what's the best move?

Yes, you're right, there is no forced win. With correct play, White avoids the mate, and Black can only win one of the two pawns he is currently behind. White will have a healthy pawn more with best play from both sides:
rn3rk1/pp3ppp/3b1n2/2pPq3/2B1P3/1NN2bP1/PPPQ1P1P/R1B2RK1 b - - 0 1

1... Qh5 2. Re1 Ng4 3. h4 Ne5 4. Bf1 Bxe4

Nice one. Given the book is from the pre-computer age, then the authors' line may have been the game continuation

Yes, many old tactics books suffer the same fate.

Granted that 2 Rf1 is much stronger than the book defense,  the final position still looks dangerous to White (5 Be2(g2) Nf3+ 6 Bxf3 Qxf3).  Maybe better 4 Be2 instead of 4 Bf1, e.g. 4 Be2 Bxe2 5 Qxe2 Nf3+ 6 Kg2 (not 6 Kh1/f1 Qg4) Nxe1+ 7 Qxe1 with equal material and little attack left.

@NoamD.Elkies : I agree, but notice that 5 Be2 Nf3+ 6 Bxf3 Qxf3?? leaves the Be4 hanging. 6...Bxf3 should yield sufficient compensation, however. If 5.Bg2?!, 5...Bxg2 looks stronger, e.g. 6.Kxg2 Nf3 7.Qe2 Nxe1 8.Qxe1 and compared to your variation with 4.Be2, white has lost the Pe4 for nothing.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
Let's beat the Benko Gambit!
I play 1. d4 as White and I have success against almost all Black defences, except the Benko Gambit, where I score about 30%.
My style is that I like solid, closed, positional games if I can, but I can handle myself tactically too. However I find that I lag behind in development, and to make matters worse, even if I reach an endgame, the Benko structure is quite solid, so even here Black has good chances.
Can you suggest a variation for White that leads to a solid, positional game against the Benko Gambit?
My elo is 2050.

I believe the Benko Gambit is refuted at high level.

Are you FIDE 2050 and can't cope with Benko?

Most of the lines where you decline the gambit (e.g. with 4. Nf3) lead to fairly closed positions.

Could you give some of your games where Benko went wrong?

Taking b5 and a6 is good, then both e4 and g3 systems should be fine.

@ferit : is there anything surprising with that ?

I play Benko as black and am a FM. The most trouble I have in quick games is with declined cxb5 a6 b6 line. Without the a line open I just do not have the play that Benko player craves.
Also, I noticed that stronger(IM+) players tend to go for the b6 line, while weaker players either take the pawn on a6 or decline the gambit with something else. For example allowing black to push to b4 has been good for me as black.

I agree about b6. The c4 square is wonderful for White to place a minor piece on, and the a4 push forces Black to pick poison...allowing a5 means cramps, and playing a5 gives White a nice hole at b5. You probably know this, being an FM, but if others are curious, there it is.

I didn't exactly take into account your style, but in your own interest you should be ready to play different position types. This isn't going to be so closed, but it will definitely be solid, positional, and you will need to be tactically astute in the moves that follow.
One of the best lines is the following.

d4 Nf6
c4 c5
d5 b5
cxb5 a6
bxa6 Bxa6
Nc3 d6
Nf3 g6
e4 Bxf1
Kxf1 Bg7
g3 0-0
Kg2 Nbd7
a4!

there are some move order wrinkles possible during this but you will manage to reach this tabiya 95% of the time. From here you just have a plan to regroup and neutralise the pressure black has on your queenside. knights on b5 and c4 for example are really nice and Qe2 or Qc2 are useful to protect b2, you can also regroup the darksquared bishop to c3. Sometimes you'll move the rook to a2 and then play b3 thought care should be taken. Also developing the hrook somewhere at some point. Subsequent to consolidating you then have good chances to slowly try to make the pawn count. This is vague but you should analyse from here yourself as it's already quite deep. Hope this helps.
EDIT:
Another option which I frequently use is to simply play 3. Nf3 when you can get some closed English/Maroczy bind position type... or if black insists on playing b5 then a6 you can take all of the pawns (including c5) and black is temporarily down two pawns and will be unlikely to recover them or get sufficient compensation.

I've been playing Benko for many years as a FM and I am generally happy to see such a tabiya, I have a lot of play as black (b line has to be protected c4 break is indicated). Maybe there is a high level refutation in this but it seems white has to sidestep a lot of pitfalls, which is what the OP wanted to avoid.

Just out of curiosity, what continuation are you usually going for? I actually have some rather detailed notes on the most natural continuations from here. I only got to play it in a tournament game once though, against a pretty decent junior. The result was very nice though and I played a good game. I reached 23. Rxe7 (the last move in my notes for this Rxb2 variation) using around 15 minutes of time (I had to recall a few lines along the way) meanwhile my opponent was actually already down to below 6 or 7 minutes.
http://www.viewchess.com/cbreader/2016/1/20/Game142162868.html

That was a nice win although I think you dropped a rook to Nb3 fork at the end :) The 21. e5 was a nice shot.

The 21. e5! is crucial to get rid of the bishop. I'd probably avoid the 12. ... Qa5 and play Qb6 (going with Nf6-d7(g4)-e5 possibly throwing in h5 and working to keep the bishop. White obviously has the edge due to the pawn, but has a lot of work ahead to convert.

In the game as well, after the exchange sac, white had a lot of trouble converting and in fact it was not that clear, I think g4 was a mistake for black, one false move by white and those connected c/d passers become scary.

oh darn, i'm pretty sure I input this king move allowing Nb3+ into chessbase wrongly dope, good spot. Yes it is quite challenging but objectively I think it should be winning with excellent technique. It's also the kind of position where black will be unlikely to be able to force matters, and so will often be a 100 move torture to hold. I agree that g4 was a positional mistake though and this kind of weakening move was all I needed to make conversion that bit easier.

also you are absolutely right about e5 being crucial. This is actually the crux of this whole variation, after the game it turned out that my opponent missed this whole idea and was feeling confident about his position at move 20.

This a4 is strong pc move but for calm play Re1 is also more than ok.

authors: Denis Карпов


text:
iOS app that calculates multiple lines
Does anyone know of a chess engine for iOS that calculates and gives multiples lines when analyzing positions? I currently use Stockfish, but it only gives one variation.

My strong SmallChess iOS app. Multi-lines is supported:

You can also try each variation on a variation board:

Where is it available?
Could not locate it on AppStore

@pabitrasaha Google "SmallChess iOS".

@StudentT I've found it under "SmallChess". When I searched for "SmallChess iOS" it didn't find anything. Will it be available for iPad? Or do you have another app that does similar for iPad?

@BU982T I am working for iPad update. This is a hobby project so I am doing as best as I can.

@StudentT I'd love to see it on iPad. Thanks!


text:
What is the longest current tablebase mate with a unique optimal line?
Having been inspired by an article on ChessBase.com, what is the longest current tablebase mate with a unique optimal line?
By unique, I mean for each of the winning side's plies, there is only one move that gives a shortest forced mate. and for each of the losing side's plies, there is only one move that gives a longest forced mate.

What does unique optimal line mean? Do you mean, there is only one option in each move?

I mean {for each of the winning side's plies, there is only one move that gives a shortest forced mate} and {for each of the losing side's plies, there is only one move that gives a longest forced mate}.

Got it. I bet its not longer than 30 moves.

I remember I saw something like forced-mate in 250 moves.

Those maximal-length wins are almost never unique even in the weaker sense (that's more standard in chess problems) that at each point the defender has at least one (co-)optimal move that makes the attacker's reply unique.  If I remember right, the ending KBN/K has such a line that's a mate in 30 or so.

@NoamD.Elkies :  One would get an interesting intermediate notion (that I might ask about later) by replacing "at least one" from your comment with "a unique".

Guy Haworth gives an answer to this in his Chess Endgame Records.
[fen "8/8/7p/7n/k7/8/2K5/3R4 w - - 0 1"]

1. Rd4+! {dtc/m/z = -26/-49/-17m} Ka3 2. Kd3! Kb3 3. Rd6! Kb4 4. Kd4! Nf4 5. Rb6+! Ka5 6. Rf6! Ne2+ 7. Kc4! Ng3 8. Rg6! Ne4 9. Kd4! Nd2 10. Rg2! Nf3+ 11. Kc5! Ka6 12. Rg6+! Kb7 13. Kd5! h5 14. Rh6! h4 15. Rf6! Ne1 16. Rf1! Nc2 17. Rb1+! Ka6 18. Rb2! Ne1 19. Ke4! h3 20. Rb1! Nc2 21. Kd3! Na3 22. Ra1! h2 23. Rxa3+! {KRKP: dtc/m/z = -3/-15/-3m} {Nalimov and Lomonosov DTM EGTs} *

Haworth states that this is the longest-known decisive AUMS, Absolutely Unique Move Sequence, known to the author.
This move-sequence arose from White and Black adopting the following strategies. White's strategy is: first, preserve the value, i.e. keep the position won for White; second, maximize DTM. (Why "maximize" and not "minimize"? I don't know, but in the above line White has only one value-preserving option at each move anyway, so it doesn't matter.) Black's strategy is to challenge White to find the unique value-preserving move.
Every move in the above line is optimal for the player's strategy. In the cases of Black's 20th and 22nd moves, there is not one unique option which is optimal for Black's strategy, but for all Black's other moves the move given above is Black's only option which implements Black's strategy of giving White only one option which keeps the position won for White.
Note that the identity and length of the longest decisive AUMS depends on what White's and Black's strategies are. Black's strategy of preferring "restrict White to a unique winning move" seems calculated to enable there to be long AUMSes. If, instead, Black adopts the strategy "maximize DTM", then the game proceeds differently. 18...Ne1 is indeed Black's only option which gives White only one winning move, but it loses in 20 moves. By contrast, 18...Ne3 loses in 32 (i.e. keeps Black alive for 12 moves more); 19. Kc6 then wins in 32, and 19. Kc5 in 34.
Some of the jargon explained:
decisive: ending in checkmate, not in stalemate
AUMS: Absolutely Unique Move Sequence
DTC: depth to conversion (i.e. depth to capture, promotion, or the end of the game)
DTM: depth to mate
DTZ: depth to changing which ply is the earliest at which a 50-move-rule draw may be claimed (i.e. depth to capture, pawn-move, or the end of the game)
value: whether the position is (with best play) won for White, won for Black, or drawn
Upper-case DTC/M/Z refer to white; lower-case dtc/m/z refer to Black.
Depth is measured in plies, where a ply is either a white move or a black move.
Haworth cites Conrady, 2003; van der Heijden #70232, (2010). The relevant entries in his bibliography are:
Conrady H. (2003). Computerschach und Spiele, Vol. 2, No. iv-v
van der Heijden, H. (2010). http://www.hhdbiv.nl/. ENDGAME STUDY DATABASE IV
The longest AUMS I can see in Haworth which ends with the mating move is a 13-ply KNkp mate. Using Nalimov I have extended it back for a further two plies but only by dint of captures.
[fen "8/8/8/1p6/b1R5/8/N7/k1K5 w - - 0 1"]

1.Rxa4! bxa4 2.Nb4! a3 3. Nc2+! Ka2 4. Nd4! Ka1 5. Kc2 Ka2 6. Ne2 Ka1 7. Nc1 a2 8. Nb3#! {Nalimov and Lomonosov DTM EGTs} *

Strictly speaking this uses a different definition of optimal than the (comment below the) question.

Thanks for alerting me to that. I have added a move-sequence which is optimal on that basis all the way to checkmate. It is only a stopgap and I make no claim that it is the longest.

Any position with seven pieces or less qualifies as tablebase position. Chess composers call composed positions with seven or fewer pieces "miniatures". By looking for  “miniatures” in the Die Schwalbe Chess Problem Database, I found new records.
Here is the longest unique tablebase mate. It has a length of 39 plies.
[Title "Victor Cuciuc, E191 diagrammes, 8/5/1984, Mate In 20 Moves"]
[FEN "8/P7/8/8/8/n6q/2p2K2/r6k w - - 0 1"]

 1. a8=Q+ Kh2 2. Qb8+ Kh1 3. Qb7+ Kh2 4. Qc7+ Kh1 5. Qc6+ Kh2 6. Qd6+ Kh1 7. Qd5+ Kh2 8. Qe5+ Kh1 9. Qxa1+ Nb1 10. Qa8+ Kh2 11. Qb8+ Kh1 12. Qb7+ Kh2 13. Qc7+ Kh1 14. Qc6+ Kh2 15. Qd6+ Kh1 16. Qd5+ Kh2 17. Qe5+ Kh1 18. Qe1+ Qf1+ 19. Qxf1+ Kh2 20. Qg2#

For six pieces, this is 31 plies..
[Title "Johannes Steinmüller, Schach 12/1996"]
[FEN "8/3p4/8/8/8/p1p5/2K5/k4N2 w - - 0 1"]

1. Ng3 Ka2 2. Ne2 Ka1 3. Nc1 d5 4. Ne2 Ka2 5. Nxc3+ Ka1 6. Ne2 Ka2 7. Nd4 Ka1 8. Nc6 Ka2 9. Nb4+ Ka1 10. Kc1 d4 11. Nc2+ Ka2 12. Nxd4 Ka1 13. Kc2 Ka2 14. Ne2 Ka1 15. Nc1 a2 16. Nb3#


text:
Which piece should I move and where should I move it when playing against black in chess when I have the first move of the game?
What is the first piece I should move as a novice chess player when beginning the game on the white side as a defensive strategy?

See also: http://chess.stackexchange.com/questions/1960/good-openings-for-a-beginner-for-white

You are white, you go first and black can't threaten you in any way yet. Why think of defense?

There is no magical move that will solve your opening problems. But if you learn opening principles you can find the correct moves for solving your problems your own.
I recommend you to read this: http://www.chess.com/article/view/the-principles-of-the-opening
I also found this video quite entertaining: https://www.youtube.com/watch?v=lNO9KCloLRE
Also check these opening traps: https://en.wikipedia.org/wiki/List_of_chess_traps

IMO, learning some "basic rules of thumb" (such as the well-written principles of the opening linked in this answer) is a great way to "jump start" learning.  They're not going to be right every game, but just having them in mind will improve a beginner's play drastically.

If you want to play "defensively" as White, start with 1. Nf3. a) This develops a piece. b) It delays moving a pawn, and gives Black a chance to "commit" first. c) It prevents Black from playing e5 without further preparation. d) It starts preparing for castling king side.
Your next move is to move a pawn, probably g3. Then move the light squared bishop to g2. Then you can castle, O-O, with a maximally secure king side, protected by both a knight and a bishop.

It depends.There are tons of openings and tons of variations that arise from them. So you may want to learn openings first to know what and what you might be comfortable with. Check out http://www.chessfiles.com/openings.html for openings and variations. They are available in PGN format as well if you want to use it with a GUI. Have fun

I have a strategy that works like this:
G1F3
B1C3
H2H4
A2A4
H1H3
A1A3
E2E4
D2D4
F1E2
C1D2

Hope this helps.

As amusing as that is, I don't think that's the best opening for a beginner...

@Ghotir I don't see how it's amusing. If it is, it was not intended and I assure you it works for me, providing the opponent does not take the frontmost two pawns. Even if this occurs, it is still possible to win with this beginning strategy.

I meant no offense (and you'll note I did not vote down).  It's the development of the rooks I find amusing - in large part because it prevents White from castling, which can be an incredibly powerful tool.

Okay, thank you. I do not castle often (gasp) and so did not notice. :-) The reason I do this is to protect that line from attack by the black pieces, since they cannot move to anywhere along that line without protecton.

You have bishops moving sideways?

@Glorfindel I interpreted that to be F1E2 and C1D2 for the last two moves.  Only thing that made sense.

@Ghotir: This is a "beginner's" (but bona fide, if ineffective strategy).Someone tried to teach me a variation of this when I started out.

Oops. I did mean F1E2 and C1D2. Sorry about that.


text:
Should white be able to win this endgame?
Should white be able to win from the position
[fen "8/5k2/3p1p2/3PnP2/1KP1r1P1/8/3RB3/8 b - - 0 67"]

with black to move?

(A game I was playing ended there when black just let

black's time run out due to having very little of it left.)

Black can take the g4 pawn, but Stockfish evaluates that as being much worse than

black's alternatives, regardless of whether the capture is immediate or after Ke7 Kb5.

Thus, play should presumably continue Ke7 Kb5 Nd7, resulting in the position
[fen "8/3nk3/3p1p2/1K1P1P2/2P1r1P1/8/3RB3/8 b - - 0 69"]

with white to move.  From that position, Bd1 is the only way Stockfish sees to make progress.

However, after Bd1, Stockfish thinks black should play Ne5, and then the line it gives is

4. c5 dxc5  5. d6+ Kd7  6. Kxc5 Nf7  7. Bc2 Re5+  8. Rd5 Rxd5+  9. Kxd5 Nxd6   ,

which results in a draw since

with white's pawn still on g4, Nf7 will establish a fortress because black can play Ke7 and N(x)g5 and even if white gives up the g4 pawn, white's king can't attack more than one of {h3,e4,h7}

and the only way for the bishop to do that is from g2, which leaves f7 safe for the knight
and
g5 fxg5 gives a tablebase draw, regardless of whether white plays that immediately

or after Ba4+ Ke7, and Ba4+ Ke7 Be8 Nxe8 gives a tablebase win for black
.

(Reminder:  My question was at the top of this post.)

Looks dead drawn despite the apparent 2-pawn material advantage and bishop for knight because: 1) the pawn structure greatly favors the knight and greatly disadvantages the bishop, 2) the knight dominates the bishop, and 3) the black rook is in a more dominant position than the white rook as well. I only find a very slight "improvement" by triangulating the knight via 1...Ke7 2.Kb5 Nd7 3.Ra2 Ne5 4.Rc2 Nd7 5.Rd2, where now it is black to move in the original position. Nowhere near enough improvement to avoid the draw tho (5...Re3).

White's main threat is c5, which forces a pawn exchange and a passed pawn with king covering queening squares. The bishop is covering the g pawn.
Should black force an exchange of that pawn, white's rook could go to e5 and capture the d pawn, allowing a double passed pawn.
If black defends c5, white first move his king to b4 to cover the next 2 pawn squares, then force black to zugzuang(by moving rook to a file) which forces black to stop defending c5 or move the rook.
If black moves rook to e5, putting pressure on the bishop, white pins black's knight and therefore forces a minor piece exchange, with a more active king, which will then go on and promote pawns.
If black stops pressuring the bishop, the endgame should be easily winnable.
As for Ke7, idea would be the same
For moves that does not either pressurise c5 or protects d6, force an exchange on c5 and you can win easily

Possibly is what my intuition says,  but it would take a lot of analysis to know what best play result should be.
OTOH  with real people it could easily be a win if they have time pressure in a tournament.  Maybe even if not pressure just insufficient time to really do a full scale  in depth analysis of all the nuances.
If black takes the pawn and white exchanges B for N then we have a R+P endgame with white a pawn up but black's king in front of the potential passed pawn.  That would be very hard to win.  But computer analysis might show it is possible.

Stockfish 14.1 NNUE ruled this position as a win. It is indeed evaluated at 4.00 depth =56. After a Rook exchange, a second iteration in the Bishop vs Knight endgame at d=64 returns + 11.15 in favore of White. It seems a win instead, albeit a laborious one.

After  67... Ke7 68.Kb5 Nd7 I think white should try to force to get the king to c6 and next c7.
For this a plan is 69.Ra2 with the idea of playing Ra7 next Kc6 that wins on the spot.
Black can try to go back 69...Ne5, when 70.Rc2! seems to be good: holds c4 and enables the K to move.
Now on 70...Nd7 follows 71.Kc6 and if 71...Ne5+ again, 72.Kc7, with idea c5, winning. Only 72...Nf7 holds f5 a move, but after 73.Rd2 and there is no way to prevent 74.c5 +-
Black can try 69...Re3 70.Ra7 Rb3+ (70...Rxe2? 71.Kc6+-) 71.Kc6 Rb6+ 72.Kc7 Rb2 73.Ra6! is killing e.g. 73... Rxe2 74.Rxd6 +-


text:
Is any chess software specifically for forced mates?
Is any chess software specifically for forced mates?
In particular, such software can only prune the search tree when it can prove

that the the move doesn't affect the existence of length of a forced mate.

Chest UCI, which is Franz Huber's UCI-adapter for Heiner Marxen's problem solver Chest, is the obvious bet.

Joseph Ellis on talkchess has a modified Stockfish for mate solving.
Updates:

1) Sync with latest SF.
2) Move to full hash key.
3) Increase max depth to 250.
4) Improve mate detection.

https://dl.dropboxusercontent.com/u/1145468/MateFinder.7z

The archive includes the source and two very basic windows compiles.

http://talkchess.com/forum/viewtopic.php?t=58597&highlight=mate+solver
The Github URL: https://github.com/jhellis3/Stockfish/tree/mate_finder
I never downloaded the archive and have no idea how good it is. I think it might worth a try as Joseph seemed to know what he was doing.

There are some specialised programs for solving all kinds of chess problems (like Chloe or Alybadix). They can also treat a Chess position as a problem and look for mates in there.
For more information, see https://en.wikipedia.org/wiki/Software_for_handling_chess_problems


text:
What are the ideas behind the Blackmar-Diemer gambit?
I have a new chess student who likes risky openings. We conducted an exercise where we played the first 4 or 5 moves to see which openings come naturally to him. He chose the Scandinavian Defence and Queen's Gambit Accepted as Black, and the Blackmar-Diemer gambit as White.
[FEN ""]
1. d4 d5 2. e4

My problem is that I have only come across this opening once, and it does not appear in any of the books I have. It also is that my style of play is very different from my student's. I have a much more cautious style.
So, my question is, to help my student, I would like to know what are the main ideas and variations in the Blackmar-Diemer gambit?

Note that black can play 2...c6 or 2...e6 to transpose to a Caro-Kann or French, you probably do know about them.

@RemcoGerlich: Fair point. For my student I would probably advocate the Nunn-Shirov attack in the Caro, but not too sure what to advise for the French? I'll probably set up the board and see what he plays to 2...e6

@RemcoGerlich A real BDG fanatic insists on being a pawn down: 1.d4 d5 2.e4 c6 (or e6) 3.c4.

I've been thinking about your method of seeing which moves come naturally to your student and going with that. When he played 2.e4, was he sacrificing a pawn with an idea behind it? Because if he didn't, I feel he just gave away a pawn and you shouldn't treat that seriously. And if he did have an idea (like 3.f3) then it'd be interesting to us to know what it was.

@RemcoGerlich: Yep, my student's idea was 1. d4 d5 2. e4 dxe4 3. Nd2?! (instead of Nc3), with the idea of both pressuring e4 and allowing to push the c pawn to c4. We talked about how Nd2 blocks in the c1 bishop, and how white's play in most gambits is based on piece activity

If you can afford it, Shearer wrote good book on BDG, just look it up on Amazon. Also, Boris Avrukh covered BDG in one of his opening volumes. Again, simple Google search will help you find the book. These two are the best and most objective resources I have read so far.

I've used BDG countless number of times and won virtually everytime over weaker players. This is a dangerous opening if Black simply plays normal development moves, quite tricky to play in a 5-minute blitz game.
White has to attack because he is a pawn down. The most direct and surprisingly effective setup is:

Position the light bishop on the d3-h7 diagonal
Move the white queen d1-e1-h4
Prepare for an exchange sacrifice on the f-file
Prepare for bishop sacrifices on the h6 and h7 squares

Why is this effective in a blitz game? An unprepared Black player might just simply make normal development moves, as if there was no gambit. By the time Black sees the checkmate, it'd be too late. If Black plays h7-h6 or g7-g6, White has the the two bishops and f1-rook to do further damage, for example sacrificing by Bxh6.
This gambit can be refuted, possible ideas:

Castle to the queen-side
Delay castling and strike on the weak d-pawn. If white plays c3, Black has ...c5 to challenge the pawn and try to open the weak g1-a7 diagonal.

I've personally found very difficult to deal with Black castle queen-side, because it is harder to exploit the space advantage in the king-side while the Black king is on the other side of the board.
Here, I give a sample game that I've used many times.
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1.d4 d5 2.e4 dxe4 3.f3 exf3 4.Nxf3 Nf6 5.Bd3 e6 6.O-O Bd6 7.Bg5 O-O 8.Qe1 Nbd7  9.Qh4 c5 10.Ne5 cxd4 11.Bxf6 Nxf6 12.Rxf6
*

Strictly speaking 3.f3?! is the Blackmar gambit, not the Blackmar-Diemer. The problem is 3...e5! striking at white's center immediately. The Blackmar-Diemer gambit is 3.Nc3, and if 3...Nf6 4.f3 trying to improve on the Blackmar.

After 3.f3?! I have %70 something win rate with Whites, the resulting position suits me perfect somehow.

Student T covered the ideas clearly and RemcoGerlich pointed out the best counterattacks.
IM Martin has a video explaining the finer points. He has this trailer: https://www.youtube.com/watch?v=srGcegnDqz0.
I did play this opening during my teen years, and found that even if Black castles queenside, the pressure against f7 will win the pawn back.  Now I occasionally transpose into it, while playing blitz, when my opponent plays  the Scandinavian Defence.
http://tws27.weebly.com/blackmar-diemer-gambit.html has the basic opening lines.
Gary Michael Danelishen wrote "The Final Theory of Chess."  He left Fritz running for days analysing the opening, and it claims the the BDG is the best opening.  He shows the lines suggested by the computer and its evaluation.  Although I would not recommend the book, it does have interesting line for the French.

If I was trying to explain this to a beginner, I would say that black is up a pawn with no compensation.
Yes, white's position is dangerous but black is fully equal. Refer to the engine for specific lines.


text:
How do I become less materialistic?
I've identified that the weaknesses in my game are:

Materialism: Most of my wins are where I've won some material and converted the advantage in an endgame. However outside of this plan, e.g. launching a mating attack, my knowledge is not up to scratch
Missing strong sacrifices: I can see pawn sacrifices in exercises, but I know in a game situation I would not make them. After all, my materialism screams "don't make a material concession!"
Undervaluing the initiative: I tend to underestimate an initiative advantage based on superior development, both for myself and my opponent. E.g. I might lag behind in development to ensure a superior pawn structure

My question is, can you recommend a training plan to boost my understanding of the initiative and making sacrifices?
Background info:

Rated 2050 Elo
Playing 1. d4 as White, Slav and Caro-Kann as Black

With that rating, you can be my instructor. So I can't help. But, are you afraid to lose?

A suggestion I have is to start playing gambits, and high-risk-high-reward openings. For example, playing the King's Gambit as White forces you to utilize any initiative you are given. Playing the KID as Black will force you to sacrifice pieces now and then to win istead of losing.
Basically what you need to do is to start appreciating initiative by experiencing it for yourself. Otherwise it becomes very difficult to dare making risky decisions based on tempo and piece activity, if you've never done it successfully before.
Based on what you wrote, I guess you tend to play mainly rather slow and positional setups in the opening. Then you have to expect it to be rather difficult to learn about this style of play, as you are probably not very familiar with it.
Other things you can do is to look for inspiration in games by e.g. Kasparov. He was excellent at utilizing the initiative, and just crushing his opponents with daring attacks. Just look at the notable games at his personal page on chessgames.com, some of them are rather amazing examples of this.

Learn the pattern of successful attacks.  Could give pawn odds instead of familiar lines of gambits.

I would recommend playing training games in which you try to sacrifice a pawn as early as possible. Once you are down material you are forced to look for dynamic chances.
I developed into a dynamic player by playing games against an old board computer which just grabbed every pawn it could get. I quickly found out that the easiest way to beat it was to sac' a few pawns and then build a winning attack from the development advantage.
A more realistic way is probably to create a blitz repertoire consisting of gambits and to use this repertoire in online blitz. I once compiled such a repertoire for my wife, who plays extremely solid chess appr. on your level, and it did work at least short term while she was practising with it.
Such a repertoire might contain the king's gambit, the Chochrane gambit, the French wing gambit, 1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.f3, the Morra gambit for white and the Portuguese, the English wing gambit and the Schara-Henning gambit for black.
Of course it would require some study but the point is not to learn the theory really deep. You rather try to get the general idea and then just ditch a pawn and attack in every game.

One other recommendation alongside some good ones.....
Play speed chess.  In speed chess material advantage is worth less than it normally would be.  Instead, attacking is valued in this type of play more.

The key lever that stands out for me in your self-critique is the "knowledge of mating attacks" deficit. Just do a whole lot (hundreds) of mate-in-two and mate-in-three problems. It might crack the "blind spot" you are reporting in general. (I like the Polgar book ("Chess") myself for this (5000+ problems), but any reasonable source of -in-2 and/or -in-3 problems should work.)

I'm not sure that this is what the OP means when he says "knowledge of mating attacks". I think it's more like the "I will go attack the opponent's king, and it's impossible to see all the way to a mate, but I know it will work, because it is strategically justified" type of thinking that is the issue. What you're describing is lack of knowledge of mating patterns, which are essential as well, but not the same thing.

@Scounged I see what you mean. What I meant by using the term "lever" in my "answer" though is that I think studying the -in-2's and -in-3's will "bleed over" into all the other areas the OP mentioned -- initiative vs. material, sacs, and as you say, king hunts in general.

Yeah, I mentioned it mainly to emphasize that the two subjects are different in nature, not that they aren't connected to each other.

Hi @JeffY: I agree that sometimes the hardest thing to do is to spot the mate. I'm actually working through GM Ftacnik's 1000 mates to help my calculation. But the main issue I'm finding is in line with what Scounged said. I point my pieces at the enemy King, then lose the initiative, e.g. my pieces get traded off and I have no attack.

@Bad_Bishop That's interesting about pieces getting traded off. Are you familiar with Benjamin's latest book, Liquidation? It might have something for you also...

Study games of attacking players who play d4 e.g. Kasparov. Or just attacking players in general e.g. Morphy.
Read Art of Attack in chess by Vukovic.
Practice tactics especially mating tactics in the middlegame.
Find your weaknesses by analysing your own games and finding out where you could have sacrificed.

Art of the sacrifice in Chess by Spielmann is also meant to be good but I haven't read it so can't recommend.

The life and games of Mikhael Tal, Fire on Board, Storming the Barricades, … all awesome.

One important aspect that you can consider apart from Material is

Check how much Space you are occupying on a particular side of the Board .Here what I mean is sometimes your opponent has captured some Squares around your King but is material down . So when he gives up the Material (Sacrifice) to open up a line or deflect a Piece from your K-side do not accept the Material .
Follow games of Kasparov/Shirov/Fischer where they have sacrificed Material to gain Activity .
When you already have an ELO of 2000+ I do not feel you will be having difficulty in understanding the concept that Activity of Pieces is the sole purpose when you play a Chess Game .
Follow Sicilian Dragon games from Black side where Rook is exchanged for Knight on c3 . Sicilian Dragon is one of the best example for Activity instead of material .
There are a lot of tactics which focuses on Space advantage and Activity instead of Material . Practice those .

Study openings that are known for being tactical rather than positional.
Work lots of tactical puzzles (but it sounds like you already are).
Play unranked games against weaker opponents and limit your repertoire to very aggressive and sacrificial attacks.  Work your way up to stronger opponents.
Take positions you have seen in games that are dynamic and tactical (from high rated players) - enter them into a chess program and play the side of the attacker without studying the conclusion of the game.

At the end of the day, just accept that you are a positional player and enjoy being who you are.

Play the isolani like a gambit

Source: The wisest things ever said about chess by GM Soltis
Many answers have advised playing gambits (+1 to them) to learn the trade off of material with time. I've also been playing isolated pawn positions to learn more about the initiative, which even if the initiative dissipates, then the isolated d-pawn is not a fatal weakness.


text:
Why do some players never accept a draw offer?
Some of the people I play against will never accept a draw offer, even in positions that are a theoretical draw.
I know it's a draw. They know it's a draw. But they want to play until:

Draw by stalemate
Draw by insufficient material
Draw by threefold repitition
Draw by the 50 move rule

In a recent casual game (i.e. no arbiter, no clocks), my opponent forced a stupidly long draw (49 moves with no captures or pawn moves, then 1 pawn move to recent the count. Repeat until insane).
My question is, why do some players never accept a draw offer, even in dead drawn positions?

Did you ask him?

@RemcoGerlich Yep. Just a mumble of "never give up..."

play with adults, not children.

It depends on the situation. Your recent casual game sounds like an extreme case. However, generally, in other games, I would tend to say the player who angrily demands the draw is a poor sport. Really, that's what the 50-move rule is for, so that you can claim the draw by rule. I do realize that this is probably not the answer you wanted. Twenty years ago, the U.S. Chess Federation piloted a rule that terminated all games after 175 moves. The rule didn't stick, but you want something like that. It is usually wrong to be angry with a player who chooses to exercise his rights under the rules.

One reasons is the opponent is praying for a blunder or time out, especially very short timings like 1|1 or 3|0 or 5|0, or because some endgames are only drawn with 100% play, which for some endgames are extremely difficult, your opponent might hope you are not playing perfectly.

In the past some opponents would keep playing forever. Sometimes kids in real life (when I was little) but more often unknown people in online games with no or very long timecontrols. Even if it was clear that we would end up hitting the 50 move rule after 'hours'. As there would be plenty of time I would typically announce that I would go elsewhere leave them at the board for a long time before I would make another move. Usually the 'threat' would be enough to bring them to reason, but sometimes I actually had to execute. I never had the same person stall me twice after this.

I'm going to assume here you're playing against people you don't know very well in a park somewhere.
While you both know it's a draw, he's assuming that you don't know how to play it out or that you'll lose your patience and make a blunder. After you both have played against each other some time, you'll both know what you can and can't win against each other and he will offer draws out of his own initiative. Unless, of course, your opponent is very stubborn then you just have to put up with it.

I lose a pawnless rook+king vs. rook+king endgame due to impatience.  I wasn't happy at the time, but it was a valuable lesson!

@RebeccaJ.Stones Mine is worse, a queen vs a rook endgame when I can force mate

As a player who rarely accepts draws, I will try to explain why higher rated players do not take draws. For a higher rated player, even in a drawn position, the only two results are a win and a draw. Obviously, sometimes he loses, but that chance is much smaller than the chance that he wins. The higher rated player doesn't take a draw because he can usually get more from playing on. Secondly, the higher rated player knows that you will be frustrated if he grinds for the next 100 moves. Each move increases the chance you make a mistake, and eventually you get so bored of the position you make a mistake and lose the game.
Note: Don't offer draws against higher rated players unless it's three move repetition or a forced draw. Almost all of the time they decline, and you give them more confidence because it tells them that they can't lose.

Some people just have the psychology that they will not offer or accept a draw. Period.
A couple of months ago I was watching a game between a 2300 and a young (12 year old) 2050. I know the 2300. He doesn't accept draws. It's not a question of grading. Earlier he had a draw if he wanted against a GM. He played on and lost. In this game they reached a position where the 2300 had a perpetual check if he wanted. They both had about 1 minute on the clocks with 30 second increment. The 2300 didn't want the draw. He played another move instead. Now the 2050 had a perpetual. He started to play it. The 2300 deviated. Sharp intake of breath from the watching crowd. Two moves later he lost his queen and the game. He knows the 2050 player. He is not going to change. That's just the way he is.

It might be something players who know each other very well might do when they're playing casually, but I can't understand the reasoning of a player who just refuses to accept a clear draw.
My mother taught me to play when I was very young, and I played a lot against her and not much against anyone else. I don't think we had very many draws, but we never ever resigned; we always played it out to the bitter end, even in positions where it might be considered rude not to resign. This wasn't something we really talked about, but it probably helped me a lot with developing my endgame play, and with identifying mating patterns. Against anyone else, I would resign if the position warranted it, and accept a draw if one was justified, but against Mum, I guess I felt like we both learnt more from finishing the game than from just ending it with an agreed draw or resignation.

There are many theoretically drawn positions which are difficult verging on impossible to draw without prior knowledge of the drawing strategy. R+B v R is a good example. But as a player who rarely accepts draws myself can you explain why I "ought" to accept one when I don't want a draw. If it's drawn then just demonstrate the draw and stop focusing on the opponent's behavior.

Might not be what you're thinking of, but mind games. I quote from the Wikipedia article on the World Chess Championship 2010:

Topalov demanded that the match be played in silence ... Anand replied that he would not comply, prompting Silvio Danailov, Topalov's manager, to say "If Vishy doesn't agree to the rules he will be forced to, because Topalov will not offer him a draw and he will not speak to him." [and by implication will ignore any draw offer by Anand]

See the cited source.
Somehow they still managed to draw game 10 by mutual agreement, but the rest of the draws all came from 3-fold repetitions.

Some kids are taught to never accept a draw nor to resign.  They insist on being mated.  Guessing they dont expect you to accept a draw either.
I had one keep playing when he was down a QBN and insisted that I mate him.  I only played that kid once.
If there was no money on the game (or rating points)  I would just say I am leaving the game is a draw.  GOODBYE and never play them again.
But are you sure it was actually a draw.  An alleged expert came up to my game last week and said its a draw.  I said it is a clear win for my side. NOTE: This was a fun game at the club.
I won after another 20 moves.  Needless to say this expert is great at middle game sacs and attacks but he knows little to nothing about endgames.
If he would learn openings a little better and learn endgames he could be a NM or maybe SNM.

Either they are higher rated and hoping that you make a mistake, or they are total patzers who will waste your time and play every single game out to it's final conclusion because they think it's bad sportsmanship to do otherwise.


text:
Prove that White is not allowed to castle here
A friend recently gave me the following weird chess problem to solve. I'm afraid that I'm struggling to see the key idea that would ultimately count as proof. From the position, intuitively speaking, it looks like White should be allowed to castle, but I'm sure to be missing something here.
Prove why white is not allowed to castle in this position.
[FEN "1n2k3/p1pqppp1/1p1p1n2/3N2p1/1PB3bP/2P1PN2/1P1P1PP1/2BQK2R w K - 0 1"]

Before seeing what site I was on I thought this has to do with fast food...

This is actually a rather typical retrograde problem, just start with the most basic observations:

We see that black is missing both rooks and the f8 bishop. Given black's pawn structure it's easy to see that neither the f8 bishop nor the a8 rook could have escaped the structure, thus they must have been captured on the 8th row (by a white knight for example). This leaves us with the h8 rook, for which there's only one plausible choice left, namely having been captured on the b4 square by the a3 pawn.

As for white, the only missing piece is the rook, which must evidently have been captured on the g5 square by the h6 pawn.

Now we arrive at the real question: which rook could have logically been captured first, the one on g5 or the one on b4? Surely if the black h8 rook is to be captured on b4, it must first have been freed by the white rook being in turn captured on g5, but that's impossible, as the h8 rook being taken off on b4 is the very thing that must have freed white's a1 rook in the first place! Which leaves us with one remaining logical possibility: White's h1 rook must have been the one coming out and subsequently captured on g5, which then in turn frees black's h8 rook, to come out and be taken off on b4 by white, which finally freed the a1 rook.

Thus the rook you see currently on h1 is actually the rook coming all
the way from a1 (once freed), with the original h1 rook having been
lost on g5. Given this sequence as the only possible logical sequence
leading up to the current position, white cannot castle, as for
castling to be allowed, neither the king nor the rook must have
moved.

These kinds of puzzles usually go under the category of retrograde analysis, where unlike usual chess puzzles where the intent is to find the best moves/tactics or mates, in retrograde problems it's rather often just a logical question that can be answered by considering the basic rules of the game, and trying to find the only logical sequences (not move by move though, just the necessary ideas) that could have led to the position given in the puzzle. So if you're not familiar with these kinds of problems you may indeed find it difficult to attack them at first. Retrograde problems in chess are really fun to solve, specially as soon as you get the handle of them and start solving the real difficult ones. The solving process is really similar to that of a detective solving a crime, since if you think about it, you're given some clues and trying to figure out what could and could not have happened ;)

Addendum after some comments:
(This is regarding which of the black rooks may have been taken off on b4, although this fact leaves the proof unperturbed.) The a8 rook is trapped on the 8th row, as the only possible way for it to escape the 8th row would be via the h-file, which once opened (i.e white losing the h1 rook on g5) would first let the original h8 rook out. Of course you can always assume the h8 rook and f8 bishop were for example first taken off by a knight, then the a8 rook was the one coming out to get captured on b4 (e.g. Nc6, Qe6, Kd7 to open the 8th row), but for the purpose of the puzzle it won't matter, as in either scenario white wouldn't be able to castle as the same arguments hold.

Thank you so much for the step by step write up, very easy to follow. Now I see along which lines I was supposed to prove this... so curious these problems, i ll definitely try to solve more of them.

Do the moves have to make logical sense? Because I don't think the a8 rook is trapped. I agree the f8 Bishop was trapped, but it could have been captured before the a8 Rook was moved.

@TonyEnnis yes logical in the sense that they have to be acceptable by the rules of chess, but not necessarily "good moves" by any means. The a8 rook is trapped on the 8th row, as the only possible way for it to escape the 8th row would be via the h-file, which once opened (i.e white losing the h1 rook on g5) would first let the original h8 rook out. Of course you can always assume the h8 rook and f8 bishop were first taken off by a knight, then the a8 rook was the one coming out to get captured on b4 (e.g. Nc6, Qe6, Kd7 to open the 8th row), but for the purpose of the puzzle it won't matter.

@user929304: Retros are super fun, and I highly recommend starting with Smullyan's two books; they start easy and do a good job teaching different techniques for solving these sorts of puzzles.

@EricLippert I sure will, thanks. Just awesome stuff!!

@RewanDemontay Hi, I rolled back to my own version, please before changing so much, leave me a comment. All edits were unnecessary and grammar+presentation is more than serviceable here.

@RewanDemontay usually for retrograde problems proof games have little bearing, as solving the problem entails proving that a set of specific events must have taken place, as opposed to move-by-move depiction of a game (which is impossible, and non-unique). But if you feel in this case showing an example of a game helps, feel free to add one as a separate answer, but be wary that the example may carry characteristics over and above the problem here.

This problem is by Raymond Smullyan, and is from his The Chess Mysteries of Sherlock Holmes (p.54 of the Hutchinson edition).
Phonon's analysis is mostly sound, except that we don't know which black rook White's a-pawn captured. But that doesn't matter, because, before Black's h-pawn captured a White rook, neither of Black's rooks could have reached b4.

Thanks for the reference, it is a wonderful book, a real joy to read. Regarding which black rook could have been captured on b4, indeed either of them could have in principle as I also pointed out to Tony in comments.

authors: Hermia 極緻美學概念店


text:
What are the main ideas for White in the Queen's Gambit Accepted, 3.e4 variation?
What are the main ideas for White after 1. d4 d5 2. c4 dxc4 3. e4?
[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4

develop pieces and regain the pawn at c4 as soon as possible.

Black has 4 main tries and one dubious line. White's plans vary based on the tabiya. The positions below are the lines given in Starting Out: Queen's Gambit Accepted by Reatsky and Chetverik:
3...e5
[FEN ""]
[StartPly "5"]

  1. d4 d5 2. c4 dxc4 3. e4 e5 {Best and thematic. A strong central counterattack that made the 3. e4 QGA unpopular in the '80s.} 4. Nf3 {White defends the pawn and prepares to castle kingside.}

Now Black has 2 choices: 4...Bb4+ and 4...exd4.
4...Bb4+
[FEN ""]
[StartPly "7"]

  1. d4 d5 2. c4 dxc4 3. e4 e5 4. Nf3 Bb4+ {Black develops with tempo and blocks a defender of the d4 pawn.} 5. Bd2 Bxd2+ {Black is happy to trade, seeing as he is up material and has slightly less space when the c4 pawn falls.} 6. Nbxd2 {6. Qxd2 exd4 7. Qxd4 Nf6 8. Qxd8+ Kxd8 actually sucks the venom out of white's attack, as the queens are gone and the trades benefit black, whose king is open and has less space.} exd4 7. Bxc4 Nc6 8. O-O Qf6 {Black aims to play ...Nge7 and ...O-O.} 9. e5 {The queen has developed early and can be attacked, gaining space. The pawn cannot be taken due to tactics on the open e-file.} Qg6 10. Re1 Nge7 11. Nb3 {Thematically regaining the pawn.} O-O 12. Nfxd4 {The material is now even with quite even development and safe kings. But why was it the f3 knight that recaptured? Well: 1) 12...Na5, pestering the bishop, is prevented, and 2) The queen can develop to the kingside, e.g. Qf3 easily.}

4...exd4
[FEN ""]
[StartPly "7"]

  1. d4 d5 2. c4 dxc4 3. e4 e5 4. Nf3 exd4 {Black invites white to play 5. Qxd4? Qxd4 6. Nxd4 Bc5 which equalises. Similarly, 5. Nxd4? c5 6. Nf3 Qxd1+ is also good for black.} 5. Bxc4 {White should definitely develop the bishop to regain a pawn and take control of a key diagonal.} Nc6 6. O-O Be6 {Defending the diagonal leading to the weak f7 square, this almost forces a trade of a well developed piece.} 7. Bxe6 {7. Bb5 is playable. See Kaspaprov-Anand, Linares 1999} fxe6 8. Qb3 Qd7 {Why not 8...Qc8? Well this is too passive and can be punished by 9. Ng5!} 9. Qxb7 Rb8 10. Qa6 Nf6 11. Nbd2 Bd6 {The bishop develops to a flexible square that discourages e5.} 12. Qd3 O-O 13. a3 {Preventing any annoying ...Nb4 or ...Bb4 manoeuvres.} Ng4 {Black seeks to place a knight on e5, a well placed steed.} 14. b3 Nce5 15. Nxe5 Nxe5 16. Qxd4 Ng4 17. e5 Nxe5 18. Bb2 Rb5 19. Qe4 Nd3 20. Bd4 Rf4 21. Qa8+ Rf8 {With a likely draw by threefold repition.}

3...c5
[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 c5 4. d5 Nf6 5. Nc3 b5 {Principle: attacked in the centre, counter on the wing} 6. Bf4 {The Bishop thematically comes to f4 as in some variations the bishop takes on b8, often in conjunction with a rook on b1.} Ba6 {Black has to develop rapidly, as the game is somewhat open and Black is being squeezed in the centre.} 7. e5 b4 8. exf6 bxc3 9. bxc3 gxf6 10. Bxc4 {This initiates a combination that simplifies into an endgame where white plays against the pawn weaknesses on c5 and the kingside.} Bxc4 11. Qa4+ Nd7 12. Qxc4 Nb6 13. Qb5+ Qd7 14. Qxd7+ Kxd7

3...Nc6
[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 Nc6 4. Nf3 Bg4 5. d5 Ne5 6. Bf4 Ng6 {6...Nxf3 7. gxf3 Bd7 is not so strong for Black, as White now has a semi-open g-file to work with, and the White king is reasonably safe in the centre.} 7. Be3 e5 8. Bxc4 Nf6 9. Nc3 a6 {Black threatens to remove the defender of the e4 pawn with 10...b5 11. Be2 b4 12. Ng1 Nxe4} 10. Be2 {White would like to offer to trade the bad light square bishop with Nd2, when Black should preserve their light square bishop with ...Bd7} Bd6

3...Nf6
[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 Nf6 4. e5 {White gains a bit of space in this line but not much else.} Nd5 5. Bxc4 Nb6 6. Bb3 Nc6 7. Be3 {7. Nge2 is also playable, but 7. Nf3?! walks into the pin 7...Bg4, which is uncomfortable, seeing as Black doesn't mind trading his bad bishop if the question is put to it.} Bf5 8. Nc3 e6 9. Nge2 Be7 10. O-O O-O

3...b5?!
[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 b5 4. a4 {White challenges the base of the pawn chain.} c6 {Black reinforces the base...} 5. b3 {...so white attacks the head of the chain instead!} e5 {Thematic and best. Over and over we will see ...e5 as been a crucial move in the 3. e4 QGA variations.} 6. axb5 cxb5 7. bxc4 Bb4+ {Black is desperate to gain counterplay (and material!) seeing as white's central pawns are so menacing.} 8. Bd2 {Forced. Blocking with Nd2 enters into an uncomfortable pin, and Ke2 loses castling rights and blocks up the kingside.} Qxd4 9. Bxb4 Qxa1 10. Nf3 {Despite white being down in material, White has: 1) More space, 2) Better development, 3) A vulnerable enemy king, queen and rooks to go after.}


text:
How could I have won this Q vs R+N endgame?
I was playing as White in this superior position when I decided to sacrifice my Queen for Knight + Pawn:
[FEN "8/2k1r1p1/5n2/5PK1/6PP/3Q4/8/8 w - - 0 46"]

 1. Qc3+ Kd8
 2. Qxf6 gxf6+
 3. Kxf6 Ke8
 4. g5 Rf7+
 5. Kg6 Ke7
 6. f6+ Kf8
 7. h5 Ra7
 8. h6 Kg8
 9. Kf5 Kh7
 10. g6+ Kxh6
 11. f7 Kg7
 12. Ke6 Ra6+
 13. Ke7 Ra8 0-1

My thoughts were that the 3 far advanced, connected pawns would beat the rook, but I was wrong.
My question is: what is the best move and plan in the starting position shown?

Partial answer - a Nalimov tablebase says your queen sacrifice should have resulted in a draw.  Black cannot withstand your pawnroller and goes for a perpetual/stalemate combo. Your fatal mistake was 9. Kf5
[FEN "6k1/r7/5PKP/6P1/8/8/8/8 w - - 0 9"]

1.Kh5 (1.Kf5??) Kh7 2.g6 Kh8 3.f7 Ra5+ 4.Kh4 Rh5+

From the starting position, Stockfish recommended...
[FEN "8/2k1r1p1/5n2/5PK1/6PP/3Q4/8/8 w - - 0 46"]

1.Kg6 Nd7 (1... Nxg4?? 2.Qc4+ {Black can't hold the g-pawn and both white pawns will queen... it's a merciful mate in 17}) 2.Qc3+ Kd8 3.Qa5+ Kc8 4.g5 Ne5+ 5.Kh5 Nd7 {This shuffling moves shows that Black is out of ideas.} 6.f6 gxf6 7.Qc3+ Kd8 8.gxf6 Re4 9.Kg5 Re6 10.Kg6 Ra6 {Black could take the pawn, trading both his pieces for the Queen and a pawn. But then White Queens the h pawn. } 11.h5 Ra4 12.Kg5 Ra2 13.h6 Rg2+ 14.Kf5 Rh2 15.Kg6 Rg2+ 16.Kf7 Rh2 17.Qa5+ Kc8 18.Ke7 Nb8 19.Qf5+ Kb7 20.Qb5+ Ka7 21.f7 Na6 22.f8=Q Rc2 23.Qf6 Rc7+

Yep, that's pretty computer-tactical. But what you see is White pushing the King away from the pawns, and then relentlessly pushing the pawns. As an aside, it would take quite a player to separate their King from the Rook without losing the Rook to a queen tactic. Not recommended!
Here's what Stockfish thinks about the sacrifice.
[FEN "8/2k1r1p1/5n2/5PK1/6PP/3Q4/8/8 w - - 0 46"]

1.Qc3+ Kd8 2.Qxf6 gxf6+ 3.Kxf6 Re4 4.h5 Rxg4 5.h6 Rg1 6.h7 Rh1 7.Kg7 Rg1+ 8.Kf6 {Draw by repetition.} )


text:
Have there really been more books published on chess than any other sport?

In the history of sport — and publishing — it’s not even close: one sport has had more books (and for that matter, magazines, tracts, pamphlets and handbills) published about it far more than any other: Chess.

Source: publishingperspectives.com
I often hear, but have never seen justification for, the claim that there are more books published on chess than any other sport.
My questions are:

Is this true?
What are the origins of the claim?

While certainly on-topic, you might get a better/sooner answer here.

Searching Amazon.com for books on several popular games does suggest that there are more chess books that books on other games.

@CWallach The question is about sports, not games. That includes soccer, poker etc.

You might consider the impact of technology on this claim. I would be willing to bet that the claim would be more easily challenged if internet articles, postings etc. where included. For example, American football teams have at least 10 publications every day of the week, during the season, injury reports, interviews, etc.  A little math, 32 teams, 21 weeks not including playoffs, but including preseason, 10 articles per day * 7 day week (70) results in, 327021=47040 publications. For one season.

One reason is that chess players believe they can improve their game by owning many chess books and skimming some now and then, soccer players not so much.

Is the claim true?
No. Using the Google Books Library Project, there are:

233,000 results for Chess
987,000 results for Sport
472,000 results for Football

Where does the claim come from?
From Wikipedia, the claim likely originated from H. J. R. Murray in 1913:

In 1913, preeminent chess historian H. J. R. Murray wrote in his 900-page magnum opus A History of Chess that, "The game possesses a literature which in contents probably exceeds that of all other games combined."

Google Books has finally made a scan of Murray's classic A History of Chess book public-domain (as it should be, for a book published pre-1923); I've reuploaded it to archive.org here in case the one on Google Books goes down.

The sentence you quoted is from Chapter 1 Introductory (page 25), (here). The footnote says "V. d. Linde's Das erste Jahrtausend der Schachlitteratur (Berlin, 1881) gives a handlist of 3,462 works on chess and draughts. The total number of books on chess, chess magazines, and newspapers devoting space regularly to the game probably exceeds 5,000 at the present time." I wonder how many books were about football in 1913.

There is no word "English" in the claim. What about books in other languages?

The below answer is incorrect because it includes newspapers and magazines. If you go under "Advanced search" and do the same search string, you can see that the results reported on the main page include magazines and newspapers. After omitting these, google search does not give a number of results.
It stands to reason that there will be a large number of newspaper and magazine accounts about football.

And it counts only English publications. All other languages are not taken into account.

I believe that there are many more books written on fishing than on chess, but chess has many books in print from days gone by.


text:
What are the main differences between 6...Bb4 and 6...Be7 in the Panov-Botvinnik attack?
After the moves 1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nc3 e6 6. Nf3, what are major differences in plans and variations for Black between 6...Bb4 and 6...Be7?
[FEN ""]
[StartPly "11"]
[StartFlipped "1"]

1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nc3 e6 6. Nf3 Bb4 (6...Be7)

Currently I use 6...Bb4 and play against an isolated d-pawn or hanging c and d pawns. I understand these plans quite well. But often Black concedes the bishop pair and is left with a bad light square bishop, which I think is a major weakness.

According to the Game Database of ChessTempo, the mainlines of 6...Bb4 and 6....Be7 are quite similar:

6....Be7 7.cxd5 Nxd5 8.Bd3 Nc6 9.0-0
6....Bb4 7.cxd5 Nxd5 8.Bd2 Nc6 9.Bd3 0-0 10.0-0

Remarkably, the main move for the second line is 10....Be7, which transposes to the first line, but with an extra Bd2 for white. For instance, Nakamura-Wojtaszek and Motylev-Jakovenko.
Instead of 7.cxd5, white can also play 7.Bd3. In this case it is difficult to tell whether the bishop is better placed on b4 (to have the possibility to take on c3) or on e7 (to protect against the pin after Bg5).
Edit by Evargalo: The logic behind Black wanting the White bishop on d2 and not c1 is a bit complicated: In the variations with the bishop on c1, the main line (after 9.0-0 Nc6) is the logical 10.Re1, where there is a lot of theory and Black has to work hard to equalize. With the bishop on d2, however, 11.Re1?! is a dubious pawn sacrifice after 11...Ndb4! 12. Bb1 (or Be4, or Bf1, or Bc4) Nxd4, because the Bd2 interferes in the Qd1-Pd4 connection. Thus the main lines are 11.Qe2 or 11.a3, which are less direct although the opening debate remains open to this day.
Objectively speaking, the values of 6....Bb4 and 6....Be7 are probably similar. Therefore, choosing between both moves is more a matter of taste.
Note that the position after 6....Bb4 can also arise after a transposition from the Nimzo-Indian, which is the subject of another Stack Exchange question.

      [StartPly "11"]

      [FEN ""]
      1.e4 c6 2.d4 d5 3.exd5 cxd5 4.c4 Nf6 5.Nc3 e6 6.Nf3 Bb4 (6...Be7 7.cxd5 (7.Bd3) Nxd5 8.Bd3 O-O 9.O-O Nc6 10.Re1) 7.cxd5 (7.Bd3) Nxd5 8.Bd2 Nc6 9.Bd3 O-O 10.O-O Be7 11.Re1?! (11.Qe2) (11.a3) Ndb4 12.Be4 Nxd4

I think it is important to explain the logic behind Black wanting the White bishop on d2 and not c1. In the variations with the bishop on c1, the main line (after 9.0-0 Nc6) is the logical 10.Re1, where there is a lot of theory and Black has to work hard to equalize. With the bishop on d2, however, 11.Re1?! is a dubious pawn sacrifice after 11...Ndb4! 12. Bb1 (or Be4, or Bf1, or Bc4) Nxd4, because the Bd2 interferes in the Qd1-Pd4 connection. Thus the main line are 11.Qe2 or 11.a3, which are less direct although the opening debate remains open to this day.

Thanks for noticing and explaining! I was unaware of the difference, but Re1 is indeed a strong move with the bishop on c1. In fact, my statement "probably little difference" might be a bit inaccurate. Maybe you can post your comment as an answer?

I sure could, but I think it is better if all the valuable information is in one and the same answer, so I would prefer to complement your good answer with my remark. If you agree, I can do the edit.

Done. Up to you to accept the edit.


text:
Fritz for Fun 13: how do I add positions to a new database?
My aim is to create a database of endgame positions taken from Van Perlo's Endgame Tactics in Fritz for Fun 13.
I've created a new database, but I do not know how to add games or positions. How do I add content to my empty database?

This is one way to do it:

Create a text file of PGN positions
Open that PGN file in Fritz for Fun. Each PGN can be seen as a line in the database view
Either play the position against the computer, or turn the engine off and play through the variation. If your variation differs from that in the PGN, the 'new variation' dialogue box will open

I'm not familiar with Fritz for Fun 13, but I have information about Fritz 13, which I will assume is the basis for your variant.
I'll also assume that you want to add a game / position manually, rather than import one (or a collection) from, say, a PGN file.
New Game: You can enter the moves for a new game by simply setting the players to 2-player mode, instead of player vs Fritz.  If you can't figure out how to do that, turn on "Infinite Analysis" mode with Alt-F2. That will prevent Fritz from entering an engine move. Then, just enter the moves.
New Position: Choose the menu option "Insert, Position Setup". Then, clear the board (in Fritz 13, it is pre-populated with the start position), and drag-and-drop or click-click your way to populating the position. Hint: In Fritz 13, if you click the white piece in the legend, and then left click on a square, you get a white piece. If you right-click on a square, you get a black piece. So, you can save yourself about 30-40% of your setup clicks by just selecting white pieces.
Finally, specify the side to move, using the appropriate checkbox. If one of the kings is in check, of course, you cannot save the position until that side is specified as having the move.
You may have to specify castling rights (kingside and/or queenside) for either white or black or both, if the kings and rooks are in their original positions, but the setup wizard (dis-)allows that side's castling erroneously. However, the wizard settings are generally correct, in my experience.  Only when either the king or the rook have moved from their home squares and then returned to them will the wizard's settings be wrong.  Don't worry about the king being in check or any of the relevant castling squares being under attack; the move entry function will prevent an immediate castling attempt in that situation.
Then, confirm that you're done with the position setup using the Ok button. You will then have an open game window (but not a saved game).
Saving Games and Positions: The last step is simply to save the game/position. In Fritz 13, if you had clicked on a database (or had a list open) before you started the game/position entry process, that database would be where the game/position is saved by default if you use the "Save" menu item.  Otherwise, you have to navigate to the appropriate database using the "Save As..." menu option. So, I generally select my database first.
Tip: You can actually use a copy/paste operation to save the game from an open game window into a database. There are tons of ways to specify "copy", including right-clicking in the Notation pane, or by typing [Ctrl][C]. Once you've put the game in the clipboard (the results of this copy action are invisible, but trust me, it's there), you can paste it (any way you like) into a selected or open database, a Notepad window or other text editor, or an email as a text attachment.  But watch out; if you paste it into a database window, different versions of Fritz are inconsistent about whether a subsequent Replace operation will affect the pasted game.  To be safe, I close the open game window, and then open the game from the database list.  That ensures that a later Replace will put the game back in that slot.