Sevenviolets wrote on 05/26/06 at 07:30:51:
12.Bc1 Nd7 13.Bd3!? N7f6 14.c4 Ne7 15.Be3 0–0 [15...Bxd3 16.Qxd3 Nf5!?] 16.Bxg6 hxg6 17.g4! Nc8 [17...b5 18.b3 bxc4 19.bxc4 c5 (19...Nc8) 20.Qf3 Nh7 21.Nxh7 Kxh7 22.d5±] 18.Qf3 Nd6 19.b3 Qa5 20.c5 Nde8 21.Qh3 Rd8 22.Rf3! Qc3 23.Rd1 Qc2 24.Rdf1±
I think where black goes wrong in your variation is
16.hxg6?!, as one can see afterwards the black pieces (in particular the knight on e7) lack squares and have to maneuver around oddly. Secondly that move opens the h-file, so that when the queen turns up on h3 one cannot at least try h7-h6. I couldn't completely check the whole rest of the variations (I somehow feel black should not end up in such a horrible position as the end one, even after a mistake like 16.hxg6), but there is no real need (or so I suspect), because there is a much better move:
1. e4 d5 2. d4 dxe4 3. Nc3 Nf6 4. f3 exf3 5.Nxf3 c6 6. Bc4 Bf5 7. O-O e6 8. Ng5 Bg6 9. Ne2 Bd6 10. Nf4 Bxf4 11. Bxf4 Nd5 12.Bc1 Nd7 13.Bd3 N7f6 14.c4 Ne7 15.Be3 0–0 16.Bxg6 Nxg6! http://www.france-echecs.com/diagramme/imgboard.phpfen=rxxqxrkx%2Fppxxxppp%2Fxxp... Black's last move not only puts the knight on an active square where it supports e6-e5 (black should continue with that idea, even more so now, because white's bishop's pair has halved), blocks the b1-h7 diagonal (well, hxg6 obviously does that, too), keeps the h-file closed (i.e. h7-h6 is still in option if it is ever needed) and keeps all of black pieces coordinated, but also potentially creates threats on the kingside (yes, black can also do that in the BDG!).
The best I could find for white here is
17. Qc2, because 17. g4 is just bad due to 17...e5!. While after 17. Qf3 black has 2 attractive options, firstly 17... Nh4 18. Qf4 Nf5, which looks a bit weird, but seems quite good. Secondly there is 17.Qf3 e5 18. Rad1 Re8 19. dxe5 (19. Qh3 Qc8!) 19... Nxe5 20. Qg3 Qe7 21. Bd4 Rad8 22. Rfe1 c5, which as far as I can tell works (but it certainly looks a bit risky, on the other hand I couldn't actually see anything wrong with it).
The idea behind Qc2 is that it not only gets the queen of the d-file (in anticipation of e6-e5 so that doesn't lead to swapping queens), but it also exerts some potential pressure on h7 restricting the movements of the knight on g6 (which also keeps black from playing e6-e5 right away).
17... Qc7 It's not completely clear how black should play, but I like this move - for once black is also aiming at the vicinity of the opponents king, now Nf6-g4 is one idea and should white play h2-h4, then g3 looks quite inviting for the queen.
Variation A 18. Rae1 A move like 18. h4 just fails due to 18...Qg3 19. Rae1 Qxh4, that's the sort of thing 18.Rae1 is designed to prevent, however even if black does nothing something like 19.h4 is still not seriously good.
18... Ng4 19.Bf4 Qd7 20. Qd1 I tried to find something for white like 20. Rd1 f6 21. Nxh7, but it all doesn't seem to work: 21.Kxh7 22. Rf3 f5 23. Rh3+ Kg8 24. Bg5 Qd6 25. Rg3 e5 26. c5 Qe6 27. dxe5 Rae8 28. Qb3 Rf7 and black just wins.
20... e5 21. dxe5 Qxd1 22.Rxd1 N4xe5 The final position is clearly winning for black, but maybe white can improve earlier?
Variation B Considering how things go wrong for white in variation A, I suppose that
18. Rad1 would have to be the mainline. It is less clear to me how black should play than in aforementioned variation, but after a bit of thought
18...c5 does make sense (which prepares once more e6-e5, which currently fails due to 18...e5? 19.Rxf6! gxf6 20.Ne4 with serious compensation for white).
What should white play?
1) 19.dxc5 Ng4! is just bad for him, e.g. 20.Bf4 e5 21.Qe2 Nxf4.
2) 19.d5 exd5 just cannot be right, this just transforms white's space advantage on the king's side (due to the pawn on d4 controling the e5 square) into a meaningless isolated pawn on d5: 20.cxd5 Qe5 21.Bc1 Qd6!.
3) So maybe 19.Rf3, but then after 19...Rad8 I cannot see how white can avoid unpleasant exchanges usually based on the idea of ...cxd4 followed by ...e6-e5.
So, maybe the only serious options (which would of course appeal to a BDG fan) is
19.Rxf6 gxf6 20.Ne4 f5 21.Nxc5, but do those slight weaknesses on the black queenside really compensate a whole exchange? It does seem unlikely to me, but at least black now has a vague weakness. On the other hand white's pieces are hardly a well coordinated attacking force (in fact they are just standing on squares where they had to go to cope with threats by black), so I really think black should be fine, particularly if he can open some files for his rooks.