Thanks for taking a closer look with an open mindLyudmil Tsvetkov wrote:Hi Carl.carldaman wrote:Hi Lyudmil.Lyudmil Tsvetkov wrote:Hi Carl.
I did not go deep enough into the position, so I do not know if Qh5 is good or bad, but I think that the logic behind such a seemingly strange move might be as follows: when Qh5 and g6 are played, as pawns do not go back, the engine would consider that, when the black king castles short (a very probable option), the king on g8 would be worse covered by the pawn on g6 than a pawn still on g7, as in this case the king will have a pawn less immediately adjacent, and this is an important pawn. Pawns do not go back![]()
The position is still somewhat open, so g6 might be a good move, but might also be a weakness, I did not go deep enough and am undecided.
I have also been frequently 'baffled' by similar engine moves in the past, they sometime prove to have some logic behind, though.
I respect your original and independent thinking on chess, but this move is no valid "novelty", so it can't be easily rationalized. Maybe if 1 tempo, and not 2, had been lost, I might concur that inducing a "weakness" might have a point. But here, g6 is a very useful move for Black, leading to a sort of KID setup, and then Black gets in Nf6 for free as well. Deep analysis aided by the underrated and forgotten Deep Fritz 10 engine shows Black can mount a promising and swift pawn storm. DF10 may be one of the few engines that truly plays well in closed positions with flank attacks and pawn storms on the Kingside.
In my database, and backed up by extensive analysis, Nc2 or even O-O are objectively better moves for White, and the masters who played them probably think likewise.
I can post more later when I have more time.
CL
I respect your searching after the truth even more, and, after looking more carefully at the position (my first suggestion was just a hypothetical assumption), my opinion is that 10.Qh5 is indeed a bad move (at least imperfect). I would play 0-0 instead (but those are just intuitive assessments, as I do not follow theory at all).
I think that after 9.Bd3 f4 black is actually better, although the position is not as much closed to empower the chain. I would play 9.ef5 instead (Bf5 Bd3), maybe white is better here.

Book ended on move 8 actually, and Stockfish chose 9.Bd3 after almost 2 minutes of thinking time. This further suggests it wasn't worried about the ensuing structure. On top of that, I strongly suspect it has an issue with the way it values tempos -- in a recent post of yours, the PV showed SF was dilly-dallying with Nf6-e8-f6 in the face of a strong attack.
Anyway, 10.Qh5 doesn't have to be a losing move to be bad. With correct play for Black, White could come under severe pressure. I've done some more analysis enlisting Houdini Tactical and Komodo CCT in addition to Fritz 10 and other engines. It is quite entertaining, and not necessarily meant to be the best possible play for either side, but just an illustration of the attacking themes and potential pitfalls facing White.
[pgn]
[Event "some analysis"]
[Site "Neo-Sveshnikov"]
[Date "2013.??.??"]
[Round "?"]
[White "Stockfish"]
[Black "Komodo&Houdini&Fritz"]
[Result "0-1"]
[ECO "B32"]
[Annotator "Doe,John"]
[PlyCount "56"]
[EventDate "2012.??.??"]
1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 e5 5. Nb5 d6 6. c4 Be7 7. N1c3 a6 8. Na3
f5 9. Bd3 {[%eval 28,27] 110} f4 {[%eval -12,26] 188} 10. Qh5+ $2 {Stockfish}
g6 {[%eval -6,26] 240} 11. Qd1 $8 {[%eval 30,29] forced} (11. Qe2 Nd4) 11...
Nf6 {[%eval -12,25] 166} 12. O-O {[%eval 30,27] 120} Be6 {[%eval -8,25] 249}
13. Nc2 {[%eval 30,27] 115} h5 14. Nd5 g5 15. b3 $5 (15. g3 $6
h4 16. gxf4 gxf4 17. Kh1 Kd7 $5 18. Rg1 $5 (18. Be2 Nxe4) (18. Bd2 Nh5 $17 19.
Be2 (19. Ne1 Ng3+ $3 $17) 19... Ng3+ $1 20. fxg3 hxg3 21. Bh5 Qg8 $40) 18...
Rb8 $5 19. Bd2 Rg8 20. f3 Nh5 21. Rxg8 (21. b4 Ng3+ $1) (21. Ncb4 $2 Ng3+ $3
$19 22. hxg3 hxg3 23. Rg2 Nxb4 24. Bxb4 Rh8+ 25. Kg1 Bxd5 26. exd5 Qb6+) 21...
Qxg8 22. Qg1 Qh7 $1 23. Qb6 Ng3+ $1 24. Kg1 Qg7 $19 25. Nxe7 h3 26. Kf2 Nxe4+
$1 27. fxe4 Qg2+ 28. Ke1 Qh1+ 29. Bf1 Bxc4 30. Qf2 Nxe7 31. Bc3 Qxe4+ 32. Kd2
Qd5+ 33. Ke1 Bxf1 34. Qxf1 Rg8 35. Qxh3+ Kc7 36. Kf2 e4 $1 37. Nd4 e3+ 38. Ke2
Rg2+ 39. Kf1 e2+ 40. Nxe2 f3 $19 41. Nf4 Qc4+ 42. Ke1 f2+) (15. b4 h4 16. h3 g4
$40 17. Kh2 Rg8 $1 $40) (15. f3 g4 16. Qe1 Rg8 17. Kh1 (17. Qh4 Nxd5) 17... g3
18. hxg3 (18. h3 Bxh3 $1 $19) 18... fxg3) 15... g4 16. g3 f3 17. Be3 h4 (17...
Kf7 $5 18. h4 (18. Bb6 Qg8 19. h4 gxh3 20. Qxf3 Qg5 21. Nc7 Rag8 22. Nxe6 Kxe6
23. c5 $5 dxc5 $132) 18... gxh3 19. Ne1 $5 h2+ $5 20. Kxh2 h4 21. Kg1 hxg3 (
21... Qg8 22. Nxf3 Rh5 23. Nxf6 Bxf6 24. Nh2) 22. fxg3 (22. Nxf3 Rg8 $40) 22...
Qg8 23. Qxf3 Qg6 $1 $17) 18. Bb6 Qc8 19. Nc7+ Kf8 $142 $1 $44 (19... Kf7 $5 20.
c5 $5 (20. Nxa8) 20... hxg3 21. fxg3 Nd7 $5 22. Nxe6 Nxb6 23. Rxf3+ $1 gxf3 24.
Qxf3+ Bf6 25. cxb6 Kxe6 $8 26. Bc4+ Ke7 27. Rf1 (27. Ne3 $5 $44) 27... Rh6 28.
Ne3 Nd4 29. Nd5+ Kf8 30. Qe3 Qh3 31. Qd2 Rg6 32. Nxf6 Kg7 33. Qf2 Kh8 34. Nd5
Rag8 35. Qg2 Qh4 36. Rf6 $5 Qh6 37. Rf7 R8g7 38. Rf8+ Rg8 39. Rf2 Rf8 40. Rxf8+
Qxf8 41. Qf2 Qg7 42. Kg2 Re6 $14) 20. Nxa8 (20. Ne3 $5 hxg3 21. fxg3 Rb8 22.
Nxe6+ Qxe6 23. Nf5 Bd8 $5 24. Be3 Ne7 25. Qd2 Nxf5 26. exf5 Qd7 $36) 20... Qxa8
21. Qd2 Qe8 $1 22. Be3 Qh5 23. Bg5 Kg7 $1 24. Be3 (24. Bxh4 Nd7 $19) 24... Bf7
25. Rad1 Bd8 $1 26. a3 Ba5 27. b4 Bxc4 $3 28. Bxc4 Nxe4 $19 0-1
[/pgn]
Some highlights from the analysis:

[d]r2q3r/1p1kb3/p1npb3/3Np3/2P1Pp1p/3B2n1/PP1B1P1P/R2QNR1K w - - 6 20
[d]7r/1p4k1/p1np4/b3p2q/1PB1n1pp/P3BpP1/2NQ1P1P/3R1RK1 w - - 0 29