Heartbyte

Leela Chess Zero – Stockfish

Top Chess Engine Championship Season 17 — Superfinal; match game 66; tcec-chess.com, April 17, 2020

King’s Indian Defence E94

Leela Chess Zero lengthened its pace as it (she) won the 66th game, thus taking a 3-point lead over Stockfish. 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Be2 0-0 6. Nf3 e5 7. 0-0 exd4 8. Nxd4 Re8 9. f3 Nc6 10. Nc2 Nd7 11. Be3 Bxc3. Stockfish ventures itself into a controversial line of theory. 12. bxc3 b6!? That’s the new move — but not much of an improvement on 12. ... Nc5 13. Qd2 Be6 14. Nb4⩲/± Miladinović – Gelashvili, 1st International Chess Open, Korinthos 1997. 13. Nb4 Na5 14. Bh6 Nc5 15. Qd4 Ne6 16. Qf2 c6

17. Rae1! Now Leela Chess Zero takes off into a sequence of “mysterious” Rook moves, in spite of its having access to two open files! 17. ... Nc5 18. h4! Qf6 19. Rc1 Bd7 20. Rfe1 Nab7 21. Nd3 Nxd3 22. Bxd3 Qe5 23. Rcd1 f6. If 23. ... Qxc3 then 24. Bc1! taking over the long diagonal a1–h8. 24. Bc2 Nd8 (24. ... Qxc3 25. Be3!)

25. c5! A powerful breakthrough at the cost of a Pawn. 25. ... Nf7. 25. ... bxc5 26. f4 is a worse version of the game. 26. Bc1 bxc5 27. f4 Qe6 28. c4 Rab8 29. h5! gxh5 30. Qh4 Qg4 31. Qxf6 Re6 32. Qc3 Rg6 33. Rd2 Qg3

34. Re3! Qxf4 35. e5! Nxe5 36. Bxg6 hxg6 37. Rxe5 Qxe5 38. Qxe5 dxe5 39. Rxd7. An asymmetrical endgame has arisen, in which White has an extra Bishop for three Pawns. Formally, Black’s compensation is sufficient, but its Pawns are too weak and shattered not to fall. 39. ... Rb1 40. Rd1 Rb4 41. Bg5 Rxc4 42. Rd6 Rg4 43. Bf6 Re4 44. a3. 44. Rxc6 Kf7 may eventually transpose into the game. 44. ... c4. 44. ... Ra4 45. Bxe5 Rxa3 46. Rxg6+ Kf7 47. Rxc6 echoes the game’s mainstream. 45. Rxc6 Kf7 46. Bg5 Re1+ 47. Kh2 Ra1 48. Rxc4 Rxa3 49. Rc7+ Ke6 50. Rc6+ Kf7. If 50. ... Kf5 then 51. Be7 followed by Rc6-f6+xg6. 51. Rf6+ Kg7 52. Re6 Ra5 53. Re7+ Kf8 54. Rc7 Ra4 55. Bh6+ Ke8 56. Rg7. Now either the a-Pawn or the g-Pawn must fall. 56. ... Rh4+ 57. Kg1 a5 58. Rxg6 Kf7 59. Ra6 a4 60. Bg5 Rg4 61. Bd8 Rc4 62. Bf6 Rc5 63. Bh8 Kg8 64. Ra8+ Kh7 65. Kh2 Rd5 66. Kg3 a3 67. Bf6 Rd3+ 68. Kh4 Kg6 69. Be7 Rd2 70. Bxa3 Kf7. Unluckily for Black, the g2-Pawn is taboo. Now Leela Chess Zero pursues its last dance with exemplary technique. 71. Kh3 Rd1 72. Kh2 Kg6 73. Bc5 Rd2 74. Re8 Re2 75. Bd6 Kf6 76. Rh8 Rd2 77. Bb8 Rb2 78. Ba7 Kg6 79. Rb8 Ra2 80. Bc5 Kf5 81. Rh8 Kg4 82. Rg8+ Kf4 83. Bd6 Rd2 84. Be7 Rd7 85. Bh4 e4 86. Bg5+ Kf5 87. Be3 h4 88. Bf2 Rd3. Or 88. ... Rh7 89. Kh3 then capturing the Pawn anyway. 89. Bxh4+− Rd7 90. Rd8 Rb7 91. Bf2 Ke6 92. Re8+ Kd5 93. Be3 Kc4 94. Rxe4+ 1 : 0.