A Certain Sum of Days

Stockfish – Leela Chess Zero

Top Chess Engine Championship Season 17 — Superfinal; match game 27; tcec-chess.com, April 11, 2020

2r3k1/q5p1/2b1p2p/n2pPp2/Pp1P4/1P1B1PP1/4NK2/3Q3R w - - 53 72

Position after 71. ... Be8-c6

In the meantime, Leela Chess Zero’s and Stockfish’s scores are still level after 27 very exciting games. In the position of the diagram, White — which needed to win to tie the scores — pulls a rabbit out of the hat: 72. g4!! fxg4 73. Qg1! The hidden pointe behind. 73. ... gxf3 74. Rxh6! Be8. If 74. ... fxe2 then 75. Bh7+ Kh8 (both 75. ... Kf7 and 75. ... Kf8 are refuted by 76. Rf6+!+−) 76. Rh4! Rf8+ 77. Kxe2+− and the curtain falls. 75. Kxf3 Nxb3 76. Rh3 Nd2+ 77. Kg2 Ne4 78. Qh2 Qxa4 79. Rh8+ Kf7 80. Rh7 Kf8 81. Qh3 Qc6 82. Nf4 Bf7 83. Qg4! g5 84. Qf3! gxf4 85. Qxf4 Qc7 86. Rh8+ Ke7 87. Qh4+ Kd7 88. Bb5+ Qc6 89. Bxc6+ Kxc6 90. Rxc8+ Kb5 91. Qe1 Nc3 92. Qa1 Na4 93. Qf1+ Kb6 94. Rb8+ Ka7 95. Qb5 Nb6 96. Qxb6 mate.

LithiumFlash, Infinite chess represented by ASCII character symbols, 2017. Courtesy of Wikimedia Commons.