The Fish Who Found the Sea

Stockfish – Leela Chess Zero

Top Chess Engine Championship Season 17 — Superfinal; match game 87; tcec-chess.com, April 19, 2020

King’s Indian Defence E94

Thanks to a powerful win in the 87th game of its match with Leela Chess Zero, Stockfish reduced the gap to a single point. 1. e4 g6 2. d4 c6 3. c4 Bg7 4. Nc3 d6 5. Be2 Nf6 6. Nf3 0-0 7. 0-0 e5 8. d5 Na6 9. Be3 Ng4 10. Bg5 f6 11. Bh4 c5 12. a3 Nh6 13. h3!? Stockfish’s una tantum code, in alternative to the manoeuvre Nf3-e1-d3, with which Vladimir Borisovich Kramink won a model game against Loek van Wely in the 72nd Corus Chess Tournament at Wijk aan Zee in 2010. 13. ... b6 14. Qd3 Nf7 15. Rfb1 h5 16. Bd1 Rb8 17. b4 Bh6 18. Rb3 Rb7 19. Qe2 Ng5 20. Nh2 Rh7 21. Rab1 Nf7 22. Nb5 Qe7 23. f3 Kh8 24. Bc2 Rg8 25. Nf1 Bf4 26. Qf2 g5 27. Bg3 Nh6 28. Ne3 Qf8 29. Bd3 Bd7 30. Rf1 Qg7 31. Qe1 Nf7 32. Be2 Qh6 33. Nf5 Bxf5 34. exf5 g4 35. Bxf4 exf4 36. h4 Rhg7 37. Kh1 Re8 38. Qd2 Re7 39. Bd1 Rg8 40. Re1 Re5 41. Nxa7 Rge8 42. Rf1 Re3 43. Rc3 Rxc3 44. Qxc3 Re3 45. Qd2 g3. Black has a Pawn less and its Queenside is on the verge of ruin, but, in true King’s Indian style, nothing is lost yet — even if by a hair. 46. Nc6

46. ... Qf8? This might be the losing move. 46. ... Ne5! 47. Nd8 (47. b5 Nc7 48. a4 Qf8! 49. a5 Qe8! seems to hold as well) 47. ... Qh7! 48. Ne6 Nxc4 49. Qc1 b5∞ was unclear but probably balanced. 47. Re1! Ne5

48. Rxe3! Nxc4 49. Qe2! Nxe3 50. Qxa6 Nxd1 (50. ... Nxd5 51. Qb7!+−) 51. Qxb6 Ne3. 51. ... cxb4 is even worse, if possible, than the text: 52. axb4 Ne3 (52. ... Nc3 53. Qd4+−) 53. b5 Nxd5 54. Qa5+− winning handily. 52. b5 Nxd5 53. Qd8 Qxd8 54. Nxd8 c4 55. Ne6 c3 56. Nd4 Nb6 57. Kg1. The endgame is won by force. 57. ... Kg7 58. Kf1 Kf7 59. Ke2 Nd5 60. Kd3 Ke7 61. a4 Kd7 62. a5 Kc7 63. b6+ Kc8 64. Kc4 Ne3+ 65. Kxc3 Nxg2 66. a6 Ne3 67. b7+ Kc7 68. Nc6 Kxc6 69. b8=Q g2 70. a7 Nd5+ 71. Kd3 Nc7 72. a8=Q+ Nxa8 73. Qxa8+ Kb6 74. Qg8 Kc5 75. Qxg2 d5 76. Qc2+ Kb6 77. Kd4 Kb7 78. Kxd5 Kb6 79. Qc6+ Ka5 80. Qb7 Ka4 81. Kc4 Ka5 82. Qb5 mate.