DDG Kmoch Variation 4.Nc3 Nf6 5.f3 Bb4

In practice this is the most common move, transposing to the Nimzo-Indian Defence Kmoch Variation. Being the most famous current player of 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.f3, super GM Shirov must have taken at least a sharp look on the position arising after 4...d5 5.e4?! dxe4.

Like in most DDG variations, Black again intends to play c5, demolishing the center. Therefore, White should immediately attack the bishop.



6.Qa4+ Nc6 7.Be3

7.a3 Bxc3+ 8.bxc3 is what I used to play a lot for some time, or was driven to play, so I started to call it the Modern Main Line. The DDG used to be so exciting with no well-known theory analysed thoroughly up to move 25, but now we have variations up to move 15 that have been played several times -- and are thus becoming "theory". Discouraging...

Black has also tried other moves after 7.a3:



8...Bd7 looks like a tempo-loss because White queen would go to c2 anyway. 9.Qc2 O-O 10.Bg5 e5 11.d5 Ne7 12.Bxf6 gxf6 13.fxe4 Ng6 14.g3, 1-0 in 25, Heikkinen - Gum, Zone 1996.

9...exf3 10.Nxf3 O-O 11.Bd3 Re8 12.O-O (12.Ne5 Nxe5 13.dxe5 Ng4 14.Bf4) e5 (12...b6? 13.Bg5 h6 14.Bxf6 gxf6 15.Nh4, 1-0 in 23, Heikkinen - Chessmaster 3000, 1995) 13.Ng5! saves the day.

Alternatives after 11.Bd3:


8...O-O looks good for Black. This is one of the key lines that needs more ideas for White: now White is desperately looking for a tempo or two to be able to create immediate threats.

9.Qc2 exf3 10.Nxf3

9.Bg5 h6 10.Bh4

9.Bf4? e5 10.dxe5 (10.Bxe5 Nxe5 11.dxe5 Re8 12.exf6? exf3+ wins) Nh5 11.Rd1 Qe7 12.Bg3 Nxg3 13.hxg3 Qxe5 14.Ne2 exf3 15.gxf3 Re8 16.Kf2 Qe3+ 17.Kg2 Bf5 0-1, Jorgensen - Heikkinen, corr. 1999.


8...h6 is based on a simple but effective idea: prevent White's bishop from coming to g5, creating an annoying pin. White could then try to attack the h6-pawn with timely Bf4 and Qd2, so Black must keep him busy.

9.Qc2 exf3 10.Nxf3 O-O 11.Be2 e5 12.dxe5 (12.d5!?) Ng4 13.Bf4 Qe7



Looks like this is almost instantly winning for Black: 6.Qb3?! c5 7.Bf4 (7.Be3 and 7.dxc5 are hardly better) Bxc3+ (7...cxd4 8.Qxb4 dxc3 9.Qxc3 -/+; but not 7...Qxd4?? 8.Rd1 +-) 8.bxc3 cxd4 9.Rd1 -/+.

Again, in practice, Black has played worse: 6...Nc6 7.Be3


Outside the two main lines, there are hardly better moves for White.