patzer2: Here's my analysis of today's Saturday puzzle (19. ?) and game with the chessgames.com opening explorer and Stockfish 8:<1. d4 Nf6 2. Bf4 d5 3. e3 e6 4. Nf3 a6> My preference is the popular move 4... c5 as in Kamsky vs Nakamura, 2017.
<5. Bd3 c5 6. c3 Bd6> More often played is 6... Nc6 as in B Nadera vs Zhou Jianchao, 2007.
<7. Bg3 Nc6 8. Nbd2 O-O 9. Ne5 Ne7>
Better here IMO is the computer choice 9...Bxe5 10. cxe5 Nd5 = (0.00 @ 34 depth, Stockfish 8) or 9...Qc7 10. Nxc6 Qxc6 11. Bxd6 Qxd6 12, dxc5 Qxc5 = (+0.08 @ 34 depth, Stockfish 8)
<11. Bh4 Nf5 12. Bg5 h6 13. Bf4 Bb7 14. h3 Be7> This slightly passive move appears to lack the activity needed to neutralize the play of the world champion. Instead, the computers prefer 14... Qc7 15. Re1 Rfd8 = (0.00 @ 27 depth, Stockfish 8)
<15. a4 Nd6 16. f3 Nd7 17. Qe2 Nf6 18. Bh2 Qc8 19. Rac1 a5>
A worthy alternative is 19... c4 20. Bc2 b5 21. e4 Qd8 22. Ra1 b4 23. exd5 exd5 24. cxb4 Nde8 25. b3 c3 26. Nb1 Bxb4 27. Nd3 a5 28. Nc5 Bc8 29. Qe3 Ba6 30. Rd1 Nd6 31. Nxc3 Re8 32. Qd2 Re2 33. Nxe2 Bxd2 34. Rxd2 Qb6 35. Rc1 Bxe2 36. Rxe2 Nb7 37. Kf1 Nd8 38. Bg1 Nc6 =.
<20. g4 Qd8 21. Qg2 Nd7 22. f4 Rc8 23. Rce1 cxd4 24. exd4 Ba8> This not at all obvious oversight, allowing 25. g5!
to
(+1.48 @ 23 depth, Stockfish 8), appears to be Black's decisive error.
Instead 24...Bh4 25. Re2 Nxe5 26. fxe5 Ne4
(+0.40 @ 24 depth, Stockfish 8) gives Black better drawing chances.
<25. g5 hxg5 26. fxg5 Nxe5 27. Bxe5 Nc4 28. Nf3 Nxe5 29. Rxe5 Bd6 30. Re2 g6 31. Qg4 Kg7 32. h4 Rh8?> White is probably winning against best play. However, this makes it too easy for the world champion, who finds the surprise winning move 33. Rxe6!! to solve today's Saturday puzzle.
Black can put up more resistance with 32... Rc7 33. Ne5 Bxe5 34. Rxe5 Rh8 but White still wins after 35. Qf4 Rh7 36. Be2 Kg8 37. h5 gxh5 38. g6 Rg7 39. Rxh5 fxg6 40. Rh6 Bb7 41. Qe5 Rh7 42. Rxg6+ Rcg7 43. Qxe6+ Kh8 44. Rff6 Rh6 45. Bh5 Rxh5 46. Rxg7 Ba6 47. Rg2 Bd3 48. Rh6+ Bh7 49. Rxh5 Qf8 50. Qe5+ Qf6 51. Qxf6#.
<33. Rxe6!! fxe6> If 33... Rc7 White wins after 34. Rxd6 Qxd6 as play might continue 35. Ne5 Re8 36. Rf6 Qf8 37. Nxg6 Re1+ 38. Kg2 Qg8 39. Qf4 Rb7 40. Rd6 f5 41. gxf6+ Kf7 42. Kf2
Re6 43. Ne5+ Rxe5 44. Qxe5 Qe8 45. Qh5+ Kf8 46. Qh8+ Kf7 47. Qg7#.
<34. Qxe6 Qe8> Not 34... Qf8?? 35. Qxg6#.
<35. Qxd6 Rc6 36. Qe5+ Qxe5 37. Nxe5 Rxh4> If 37... Re6, White wins with
38. Rf7+ Kg8 39. Rc7 Rh7 40. Rc8+ Kg7 41. Rxa8 Rxh4 42. Ra7+ Kg8 43. Bxg6 Rd6 44. Bf7+ Kh8 45. Bxd5 Rxd5 46. Ng6+ Kg8 47. Ne7+ Kf8 48. Nxd5
.
<38. Rf7+ Kg8 39. Ra7 Rc8 40. Bxg6 Bc6 41. Bf7+ Kf8 42. Ng6+ 1-0> Black resigns as White wins easy
with an extra piece and two additional pawns.