patzer2: Here's my look at today's Saturday puzzle (22...?) and game with the chessgames.com opening explorer, Deep Fritz 15 and Stockfish 8:<1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 e6> This is the most popular move in the QGD slav. The second most popular alternative is 4...dxc4 as in the drawn game Nakamura vs S Shankland, 2017
<5. Bg5> This is
the second most popular move. Most often played is 5. e3 as in White's win in
S Shankland vs Robson, 2017
<5...h6 6. Bh4> This is the second most popular move. Most often played is 6. Bxf6 as in the drawn game Van Wely vs A Giri, 2017.
<6...dxc4 7. e4 g5 8. Bg3 b5 9. Be2 Bb7 10. h4 b4> This move is seldom played, but as seen in this game can pose White considerable problems if he's not prepared for it. Most often played here is the popular move 10...g4 as in
White's win in Grischuk vs Gelfand, 2007
<11. Na4> This is OK, but the computer preference and slightly more popular move is 11. hxg4
(+0.41 @ 24 depth, Stockfish 8) as in White's impressive win in
Pelletier vs E Rodriguez Guerrero, 2006
<11...Nxe4 12. Be5 Rg8 13. Qc2>
According to the opening explorer, this is the only game in which this move
was played. The first player has had better luck with the computer preference
13. hxg4 as in White's win in
Xu Jun vs P H Nielsen, 2000
<13...c5 14. Bxc4 g4 15. Bb5+ Nd7 16. dxc5 b3!> This instructive positional pawn sacrifice is clearly Black's best move, assuring excellent winning chances if White fails to find the equalizing move 17. axb3 =.
<17. Qd3?> This appears to be White's decisive error. Certainly, it's
the point at which the first player's game takes a turn for the worse and from which he never recovers. Instead, White can hold with 17. axb3 Qa5+ 18. Nd2 Qxb5 19. Nxe4 Qb4+ 20. Nac3 Bxc5 21. Bg3 = (0.00 @ 29 depth, Stockfish 8.)
<17...gxf3>
to
(-1.56 @ 27 depth, Stockfish 8). This is probably winning, but according to the silicon monster even stronger here is 17...Bd5!
(-3.06 @
29 depth, Stockfish 8.)
<18. c6 Bb4+ 19. Bc3 Bxc3+ 20. bxc3 fxg2 21. Rg1 b2 22. Rd1?> This allows Black a clearly decisive attack after 22...Qxh4!
(-8.01 @ 25 depth, Stockfish 8.) Instead, White can put up much more resistance with
22. Nxb2 Qxh4
to
(-2,19 @ 28 depth, Stockfish 8.)
<22...Qxh4!!> This solves the Saturday Apr 29, 2017 chessgames.com puzzle with a decisive attack on the uncastled White King.
<23. Qxd7+ Kf8 24. Qd4 b1=Q 25. Rxb1 Rd8 26. cxb7>
If 26. Qe3 then Black wins after 26...Rg5 27. cxb7 Nxf2 28. Qxf2 Qe4+ 29. Qe2 Qxb1+ 30. Kf2 Rf5+ 31. Kxg2 Rg5+ 32. Kh3 Qxg1
(# 13, Deep Fritz 15 @ 24 depth.)
If 26. Qb4+ then Black wins after 26...Rd6 27. Qb2 Qh2 28. Ke2 Qe5 29. Bd3 Nc5+ 30. Kd1 Rxd3+ 31. Kc2 Qe2+ 32. Kc1 Qf1+ 33. Kc2 Qxf2+ 34. Kc1 Qf4+ 35. Kc2 Qd2#.
<26... Rxd4 27. b8=Q+ Rd8 28. Qxa7 Qh2
29. Ke2 Rd2+ 30. Ke3 Rg3+ 31. Kxe4 Rg4+ 0-1>