Heartbeats

Stockfish – Leela Chess Zero

Top Chess Engine Championship Season 14 – Superfinal; match game 100; tcec-chess.com, February 23, 2019

Sicilian Defence B99

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 e6 7. f4 Be7 8. Qf3 Qc7 9. 0-0-0 Nbd7 10. g4 b5 11. Bxf6 Nxf6 12. g5 Nd7 13. f5 Nc5 14. Rg1. In the previous, reverse game there followed: 14. f6 gxf6 15. gxf6 Bf8 16. a3 Rb8 17. Bh3!? b4 18. Nd5!? Qb7 19. axb4 exd5 20. exd5 Qxb4 21. Qe3+ Be6 22. b3 Qa3+ 23. Kd2 h5 24. Ke1 Qb4+ 25. c3 Bh6 26. Qf3 Qb7 27. dxe6 Qxf3 28. Nxf3 Nxe6 29. b4 Rb6 30. Rg1 Nf4 31. Bf1 d5 32. Ra1 Rxf6 33. Rxa6 Rxa6 34. Bxa6 Kd7 with a balanced endgame which finally ended in a draw at 95th move, Leela Chess Zero – Stockfish, Top Chess Engine Championship Season 14 – Superfinal, February 23, 2019, match game 99. 14. ... b4 15. Nce2 e5 16. Nb3!? This is a new move, probably improving on 16. f6 exd4 17. fxe7 d3 18. cxd3 b3 19. axb3 Nxd3+ (as 19. ... Nxb3+! 20. Kb1 Qa5! seems to give Black a formidable attack) 20. Kb1 Ne5 21. Qc3 Qxe7= 22. Qb4 ½ : ½ Boleslavsky – Aronin, 24th USSR Chess Championship, Moscow 1957. 16. ... Nd7 17. Kb1 h6 18. g6 0-0 19. gxf7+ Rxf7 20. Ng3 a5 21. Nd2 Ba6 22. Bxa6 Rxa6 23. Nh5 a4 24. Rg2 Nf6 25. Nxf6+ Bxf6 26. Nf1 a3 27. Ne3 axb2 28. Nd5 Qa7 29. Nxb4 Ra3 30. Rd3 Ra4 31. c3 Rb7 32. Qe3 Qa8! Leela Chess Zero goes for a double Pawn sacrifice, preferring a dynamic unbalance to a formal material equality, as after 32. ... Rxa2!? 33. Qxa7 (not 33. Nxa2?? because of 33. ... Qxa2+! with mate in two moves) 33. ... Raxa7 34. Rxb2 White’s control of the d5-square (where the Knight will plant itself) would leave it (him) with a comfortable edge. 33. Rxb2. Clearly not 33. Qxh6?? on account of 33. ... Rxa2! winning on the spot.

33. ... d5! A superb pointe. 34. exd5 Ra3 35. Qe4 Rb8 36. h4 Kh7 37. Kc1. If 37. Rg3 at once, Black can reply with 37. ... Qa4! threatening ... Qa4-d1 mate. 37. ... Qa7 38. Rg3 Qb7 39. Kc2 Qb5 40. Re3 Qa4+ 41. Kd2 Qa7 42. Ke2 Rc8! Black, in spite of being two Pawns down, has brilliantly got its (her) positional equaliser. 43. Nc6 Qa6+ 44. Qd3 Qa8 45. Qc2 Qa6+ 46. Qd3 Qa8 ½ : ½. Thus Stockfish finally won its (his) 100-game match against Leela Chess Zero by the narrowest margin of one point.

劉勃麟 (Liú Bólín), Hiding in the City – Your World, 2016. Courtesy of Galerie Paris–北京 (Běijīng), Paris.