Well, I suppose the short answer is that White avoids some of the anti-Saemisch systems, which is really the whole thing about 4.f3.  Also fwiw, 4.f3 O-O 5.a3 Bxc3+ 6.bxc3 reaches a position that many people consider promising for White.  An important point is that 6...Nh5 is met by 7.Nh3 f5 8.Bg5!.

After 4...Nc6, 5.e4 scores much better than 5.a3 in my database.  That early b6 anti-Saemisch system is one of the main ones that 4.f3 is trying to avoid, so I don't see why he would play that and then 4...Nc6 5.a3.  It's a game of chess after ...Ng8, a line relevant to the evaluation of 4.f3.  I have no particular judgment about it, but I wouldn't be so quick to say that White lacks his normal chances there.

NeverGiveUp wrote on 01/13/11 at 09:46:06:


(a) 5.e4 should be an improvement, so that line has no point
(b) after 8.Ld3 Nbd7 9.Ne2 Nf8 10.Be3 as in Yakovich - Ibragimov, Sotschi 1997, where is the fun for Black? Wherever Black castles, White can attack. In nine games in my database, Black gets away with one draw, White wins eight games.

I am an 4.f3 player, although I also play the Saemisch (4.a3) which can transpose.

I'm not afraid of d5 in particular after 5.a3 Bc3 6.bc3 c5 7.cd5: Nd5: 8.dc5: (Keres) white is doing fine. No one ever played 8. ... f5!? against me, every one goes 8 ... Qa5 9.e4.

For me the really critical lines are:
(a) 4. ... Nc6!? 5.a3 Bc3:+ 6.bc3: b6 7.e4 Ba6, and
(b) 4. ... c5 5.d5 d6 6.e4 Bc3:+ 7.bc3: e5. The latter leads to a typically Nimzo position where it's very hard to achieve anything for white.

FirebrandX wrote on 10/04/10 at 22:29:37:


you know, that is quite a clever idea in a way. Do you select on rating?

Your database "culled from ICCF" is from the ICCF games archive, right? I didn't know about this resource, and now I'm a bit confused by the many files to download, i.e. there's a file with "ICCF Server Games 2008" and also a much smaller one with "All Games Added in 2008"! Are the latter e-mail games rather than server, or what?

I bought the final edition of Tim Harding's Ultra Corr Database (3A) just before he ceased business this summer; I assume he took care to include all ICCF games up to early 2010.

Yes, that's an old book line.

I thought I might take up a 4.f3 repertoire against the Nimzo on ICCF. I got lucky in my most recent win in that my opponent chose a rather inferior line against it, though his computer almost managed to bail him out into an opposite colored bishop ending. In the end, he relied too heavily on the computer instead of intervening with human knowledge and trading down correctly into a drawn ending. Instead his computer did just enough to lose the game:

1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.f3 d5 5.a3 Be7
6.e4 c5 7.e5 Nfd7 8.cxd5 exd5 9.Nxd5 cxd4 10.Nxe7 Qxe7
11.f4 f6 12.Nf3 fxe5 13.Bc4 Nc6 14.O-O e4 15.Bd5 Nf6
16.Bxc6+ bxc6 17.Nxd4 O-O 18.Be3 c5 19.Nb3 Ba6 20.Bxc5 Qc7
21.Re1 Rfd8 22.Qc1 Qf7 23.Na5 Rac8 24.b4 Bd3 25.Qd2 Nd5
26.f5 Rd7 27.Qf2 g6 28.fxg6 Qxg6 29.Rac1 Rf7 30.Qa2 Nf4
31.Kh1 h6 32.Bd4 Rxc1 33.Rxc1 Kh7 34.Nc6 Be2 35.Rg1 Rf5
36.Be3 Qxc6 37.Bxf4 Bd3 38.Be3 a6 39.h3 Bf1 40.a4 h5
41.Qa1 Qf6 42.Qb1 Bd3 43.Qc1 h4 44.Qc8 Qf8 45.Qc3 Qg7
46.Bd4 Qd7 47.Rc1 Kg8 48.Kg1 Kh7 49.Bf2 Qg7 50.Qd2 Qe5
51.Bxh4 Qf4 52.Qxf4 Rxf4 53.Bg5 Rf7 54.h4 Kg6 55.g4 Kh7
56.Rc6 Rf3 57.Re6 Rg3+ 58.Kf2 Rxg4 59.b5 axb5 60.a5 e3+
61.Kxe3 Bc4 62.Rh6+ Kg7 63.a6 Bf7 64.Rd6 Ra4 65.Bf6+ Kf8
66.Bd4 Ke7 67.Bc5 Ke8 68.a7 b4 69.Rd4 Ra3+ 70.Kf4 Ra6
71.h5 Bxh5 72.Rxb4 Kd7 73.Rb8 Kc6 74.a8=Q+ Rxa8 75.Rxa8 Bf7
76.Be7 Kd5 77.Ra5+ 1-0

BPaulsen wrote on 04/16/10 at 17:46:15:


Now there's a claim for you.

BPaulsen wrote on 04/16/10 at 17:46:15:


And there's another.  I'll let those who play OTB sort that out, but it does look like a powerful practical argument for taking up 4.f3.  I myself don't think that White's game is so frightfully easy for an unprepared player to play, however.

In CC I rarely encounter a Black who doesn't know the "right" moves, but I do frequently encounter Blacks who have no idea of the dangers Black faces even in the lines that are nominally adequate for Black.