Early f3 in d4 openings? Are these openings playable for white? I use the first move order to counter my friend's very well prepared Benoni, and manage to whoop him many times, but its only in blitz. I was wondering if early f3s are playable in "actual" i.e. longer games as well. I'm aware that the second position often transposes into Neo-Gruenfelds or Kings-Indians, but wasn't sure if the other positions below were playable/if they provided white with good attacking chances in compensation for creating the early king-side weakness.

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1. d4 Nf6 2. c4 c5 (2... g6 3. f3) (2... e6 3. f3) (2... d5 3. f3) 3. f3 *
1. d4 Nf6 2. c4 c5 3. f3  The first two moves signify an A56 Benoni but 3. f3 does not show up in my database as a typical continuation.

1. d4 Nf6 2. c4 g6 3. f3 is a playable E60 King's Indian.  3. ... Bg7 is a good followup for Black.

1. d4 Nf6 2. c4 e6 3. f3  The first two moves signify an E00 Queen's pawn game and are very drawish.  3. f3 is not a typical continuation.  3. e3 gives White more chances for the point.

1. d4 Nf6 2. c4 d5 3. f3 The first two moves of this are also an A50 Queen's pawn game.  Again, 3. f3 is not commonly played.

I suspect 3. f3 isn't popular for good reason and would recommend you try another continuation.

EDIT - so, why is f3 bad?  In the first continuation, Stockfish believes it drops a 'pawns worth' of value:



[fen ""]
1. d4 Nf6 2. c4 c5 3. f3 cxd4 4.Qxd4 Nc6 5.Qd2 e6 6.Nc3 d5 7.e3 Bc5 8.a3 a6 9.b4 Ba7 10.c5 O-O 11.Nge2 e5 12.Bb2 Be6 13.Rd1 Re8 14.Na4 Rc8 15.Qc2 h6



We see that by after his 7th move, Black is having a splendid game.  After the moves above, Black controls the center and is doing fine.  White hasn't even castled yet.  The problem with f3, ultimately, is that it doesn't do anything to constrain Black.  It takes a good square from the Knight which will eventually deploy to the passive e2.  Further, f3 looks silly if it isn't followed by e4 sometime soon.  White only manages the passive e3. I don't like how f3 opens the e1-h4 diagonal and nor do I like how it allows a Queen or Bishop on the a7-g2 diagonal to look at the King which will likely be sitting on g1 in most variations.