I'm playing black here and reached the following position recently in an OTB game, fortunately I won. Apologies for the notation here, I don't know how to place a diagram in the post box.
1. e4 c6 2. Bc4 d5 3. exd cxd 4. Bb4 Bd2 5. Nc3 Nf6 6. Bxd7 N(b)d7 7. d4 e6 8. Nf3 Be7 9. Qe2 0-0 10. Ne5 Qc7 11. Nxd7 Qxd7 12. Be3 a6 13. Qf3 b4 14. Qg3 ...
Please try to ignore the inaccuracies by both sides up to this point, but I've lost game after game in similar kingside positions with the white bishop on the c1-h6 diagonal, and the white queen on the g file. White's threat is Bh6. The engine gives 14....b4 here, which is all well and good, however once white's knight moves out of harms way, the same threat remains. I thought 14. ... Nh5 was a decent resource, but the engine gives this a question mark. So, how does black defend here? 15.
Bh6 g6 loses the exchange, and defending the g7 pawn with only the king loses immediately. I can't find a resource in my book. It's black to move. Any ideas??
Black to play:
Not liking 15...Rfc8. I'd go for 15...Ne4 (which is surely the idea behind 14...b4.)
Then After White moves the Queen f7-f5 - which is why I like to keep the Rook on f8.
Later If White does not 0-0 and challenges the e4 Knight with Ng3 do not
take it as it opens the h-file. how about Qa5 which may squeeze out b3
and then Rac8 hitting a genuine backward pawn on an open file.
@greenpawn34 saidThank You
Black to play:
[fen]r4rk1/3qbppp/p3pn2/3p4/1p1P4/4B1Q1/PPP1NPPP/R3K2R b KQ - 0 15[/fen]
Not liking 15...Rfc8. I'd go for 15...Ne4 (which is surely the idea behind 14...b4.)
Then After White moves the Queen f7-f5 - which is why I like to keep the Rook on f8.
Later If White does not 0-0 and challenges the e4 Knight with Ng3 do not
take it as it opens the h-file. ...[text shortened]... about Qa5 which may squeeze out b3
and then Rac8 hitting a genuine backward pawn on an open file.
I haven't seen mentioned 15...Kh8, which would be my preference because it dispels the threat of 16. Bh6 without having to disrupt Black's harmonious piece setup. With a big space advantage on the queenside, I'd be inclined to dull the play on the kingside so that the only sector of consequence is the queenside.
The post that was quoted here has been removedThis prompted me to look further at 15...Rfc8 16. Bh6:
A) 16...Ne8 17. c3 (17. 0-0-0 or 17. Rc1 would lose a pawn to 17...Qa4; 17. Nf4 [threatening 18. Bxg7 Nxg7 19. Nh5] would lose material after 17...Kh8) 17...bxc3 18. Nxc3 (18. bxc3 would give White a backward c-pawn and would concede the b-file after 18...Rab8) 18...Rab8 19. Bc1 (19. Rb1 or 19. b3 would lose material to 19...Rxc3) 19...Bb4 20. Bd2 Nd6 (heading for one of several inviting light squares), and Black has strong pressure.
B) 16...g6
B1) 17. c3 bxc3 18. Nxc3 Rab8 19. Bc1 Bb4 20. Bd2 (20. Qe5 Ne4 [threatening 21...Bd6] 21. Bh6 f6 22. Qf4 Nxc3) 20...Bxc3 21. Bxc3 (21. bxc3 Rb2) 21...Ne4 22. Qd3 Qb5 23. Qxb5 Rxb5 24. Rc1 Nxc3 25. bxc3 Rb2, winning a pawn.
B2) 17. Qd3 Qb5 18. Qxb5 axb5 19. Kd1 Ng4 20. Be3 Bg5! 21. Bxg5 (21. Kd2 Nxf2!) 21...Nxf2+ 22. Kc1 Nxh1 23. Be3 b3! 24. c3 Rxa2 25. Rb1 b4 26. Kd2 Rc4.
These lines convinced me that by expending a tempo, 15...Kh8 would lose much of Black's initiative, so I didn't even analyze it. In contrast, 15...Rfc8 defers making a purely defensive move until White has expended a tempo to threaten mate.
Between 16...Ne8 and 16...g6, the former constrains White's queen to maintain the pin until the bishop has retreated from h6. This isn't true of 16...g6, which lets White's queen reach the d3-square to try to buttress the queenside. (That 16...g6 weakened Black's kingside didn't seem significant.)
The value of 16...Ne8 in deferring White's queen's arrival on the queenside seems well worth the temporary displacement of Black's knight.
This distinction seemed to be reflected in the continuations. Black's play after 16...Ne8 seems fairly straightforward, but 16...g6 17. Qd3 seems to require sharp tactics from Black in order to make progress.
So, it seems to me that 15...Rfc8 was correct, and that 16. Bh6 is best met by 16...Ne8.
But Black would have retained an edge after any of these continuations. So, in that sense, Black's decision at move 15 wasn't critical.