Smyslov_Fan wrote on 09/14/11 at 16:49:53:


But in that game 12...dxc3 is a game-losing blunder (though it still took good play by White to win). 12...Bb4 seems like a much more critical test.

Here's a line against Bd7 that I rather like for white:

[PlyCount "33"]

1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 dxc4 5. a4 Bf5 6. Nh4 Bd7 7. e4 e6 8. Bg5
h6 9. Bxf6 Qxf6 10. g3 {Now Black has three choices: 10...b5 is the most
thematic, but he could also try 10...c5 or 10....Bb4} (10. Nf3 b5) 10... b5 (
10... Bb4 11. Bxc4 c5 12. e5 {And I prefer White's spatial advantage.} Qe7 13.
O-O cxd4 14. Qxd4 {Firebird considers the position about equal at a depth of
20 ply. This makes sense since Black has a bishop pair and the position seems
to be opening up. However, White still has the initiative. Here's a sample
line:} O-O 15. Rfd1 Rd8 16. Bd3 Nc6 17. Qe4 g6 18. Ne2 Bc5 19. Nf4 Be8 20. Nh5
Nxe5 $1 21. Qxe5 gxh5 22. Qxh5 Qg5 23. Qe2 Bc6 24. Rac1 {And although Firebird
gives Black a miniscule edge, I think White's position is easier to play.}) 11.
axb5 cxb5 12. Bg2 Nc6 13. e5 Qd8 {In this main line,  White has scored well
both by playing safely with 14.0-0 and with the gambit line 14.d5!?} 14. O-O {
This is my preference.} (14. d5 Nb4) 14... Rb8 15. d5 Nb4 16. Qh5 Qg5 (16...
Qb6 17. d6 Nd3 $1 (17... a5 18. Rae1 Nd3 19. Re3 $16) 18. Be4 (18. Nd5 $5 {
This sac is probably dubious, but it illustrates some of the very real
practical difficulties Black can face in this line.} exd5 19. Bxd5 Kd8 $1 20.
Nf3 g6 21. Qh4+ Ke8) 18... Qc5 19. Bxd3 cxd3 20. Ne4 Qd4 21. Qf3 $16) 17. Qf3 {
And white must have an advantage due to his better development and concrete
threats.} *

Ludde wrote on 09/08/11 at 13:37:26:


After 10. f3 white still wants to exchange the knight but in a more favourable square. But black has not problems in this lines nowadays.

After 6...e6 It's true that white has the bishop pair but i'm not very fond about the c1 bishop. And i'm not very sure about white's structure is better than black's (look that a4 pawn) either. In the midlegame black has the e file and a nice post in e4. I tried this 6.Nh4 but concluded there's no advantage after e6.
In the dutch variation, say 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 dc 5.a4 Bf5 6. e3 e6 7.Bc4 Bb4 8.0-0 0-0 (or Nbd7) 9. Nh4 Nbd7, 10. f3 is more played that 10.Nf5

Nh4 in the Slav can occur on several different moves and they often transpose. 

It's one of white's main ideas in the Slav and should be respected. Having said that, I've defended this line in several correspondence games and actually have a plus score as Black. Ok, in truth Black was struggling in every game and my opponent in one game missed a very subtle transposition that got him into trouble. 

I wouldn't like the prospect of defending this line against a very strong player with the clocks ticking, but at least I know that Black should be able to hold.