PawnSac: < 1.c4 g6 2.d4 Nf6 3.Nc3 d5 4.Nf3 Bg7 5.h4 c6 >
5...c6 does not offer black many active prospects.
The CG database also gives a very poor impression of this move.
5...dxc4 leads to an equal game.
< 6. Bg5 >
Stockfish gives 5.cxd5 as best at 27 thru 32 ply,
but Bg5 is a sensible move. If ..dxc4 then 7.e3
and white has steered for a conventional QG
orthodox type pattern with early h4. There are
also interesting possibilities with Bxf6 and h5.
White attacks d5 encouraging ..dxc4 yielding e4 to white.
< 6...Nbd7 >
Here black played 6...h6 in
Hikaru Nakamura vs Peter Svidler
FIDE Grand Prix Khanty-Mansiysk (2015) ˇ Gruenfeld Defense: Three Knights Variation (D90) ˇ 1/2-1/2
After 6...Nbd7 white's plus jumps slightly. Black is
trying for a solid QGD position, but if not
careful he will run into some wrinkles.
< 7. cxd5 Nxd5 >
7...cd5 8.Qb3 Nb6 9.e3 O-O 10.Bd3 Be6 = see..
Alexander Ipatov vs Ernesto Inarkiev
European Individual Championships (2014) ˇ
Gruenfeld Defense: Three Knights Variation (D90) ˇ 1/2-1/2
< 8. h5 >
< ...Nxc3 9. bxc3 Qa5 >
9...Qa5 gives white a 1/2 pawn boost. ( 9. ..h6 = )
< 10. Bd2 Qd5?! 11.Rh4 >
Interesting but probably not as good as 11.Qc2.
Be that as it may, Simon certainly has his opponent
out of "book".
< 11. ..e5 >
..f5 ( -0.48 ) to restrain e4
< 12.e4 > white's plus starts to climb again.
< 12. ..Qd6 13.Qb3 a5?! >
..a5 is a bit slow. Stockfish prefers ..Nb6 here to activate the Bc8
< 14.a4 Bf6?! 15.Rh1 >
The immediate 15.hxg! (+1.23) is stronger, but it looks like Simon
understandibly wants black to castle into his attack, afterwich at the
very least white should retain a lasting initiative on the K side.
Since black has been faultering already, I too would probably be thinking
"Give him enough rope and he will hang himself."
This is one of those situations where humans and computers think differently.
Objectively though, Rh1 does constitute a loss of a tempo.
< 16. Bc4 > (+0.24)
Better is the immediate 16.hxg (+0.64). Bc4 allows 16. ..g5
and white's h pawn can no longer open the file.
< 16. ..O-O? >
If i identified any move as "the losing moment" it would be now.
Black plays into white's hands (castles into white's attack), and
white's stockfish eval immediately jumps by more than a pawn.
< 17.hxg6 hxg6 18.Rh6 >
Stockfish considered two candidates in this position; Rh6 and Kf1.
Strangely enough it selects Kf1.
36/69 7:31:21 13,184,835k 487k +1.21
Ke1-f1 b7-b6 Rh1-h6 Kg8-g7 g2-g4 e5xd4 c3xd4 Nd7-c5 Qb3-e3 Qe7xe4
g4-g5 Bf6-e7 Kf1-g2 Qe4xe3 Bd2xe3 Nc5-e6 d4-d5 c6xd5 Bc4xd5 Ra8-a7
Ra1-h1 Rf8-g8 Be3xb6 Ra7-d7 Bd5xe6 f7xe6 Nf3-e5 Rd7-d5 f2-f4 Rd5xe5
Bb6-d4 Bc8-b7+ Kg2-g3 Bb7xh1 Bd4xe5+ Kg7-f7 Rh6xh1 Be7-b4 Rh1-h7+
Kf7-e8 Kg3-g4 Bb4-c5 Rh7-b7 Bc5-b4 Be5-d4 Bb4-d2