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.

Thinking Machines

Leela Chess Zero – Stockfish

Top Chess Engine Championship Season 14 – Superfinal; match game 85; tcec-chess.com, February 20, 2019

King’s Indian Defence E87

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 0-0 6. Be3 e5 7. d5 Nh5 8. Qd2 Qh4+ 9. g3 Nxg3 10. Qf2 Nxf1 11. Qxh4 Nxe3. David Ionovich Bronstein’s controversial Queen sacrifice: Black gives up Her Majesty for two Bishops and a Pawn, and will win a second Pawn after 12. ... Nxc4. But theoreticians still do not agree whether or not Black’s positional compensation is sufficient. 12. Ke2 Nxc4 13. Qe1!? Mankind probably thought better than what machines calculate: 13. Rc1 Na6 14. Nd1 Nb6 15. Nh3 Bd7 16. Ne3 f6 17. Rhg1 (17. Nf2 Nc8 18. Rc3 Ne7 19. Rhc1 Rac8 20. Rb3 Rb8 21. Nd3 Rf7 22. Qe1 Nc8 23. Qa5 Nb6 24. Rxc7 f5 25. Rc2 fxe4 26. fxe4 Rbf8 27. Rxb6 ½ : ½ Kasparov – Seirawan, 4th Grandmasters Association World Cup Tournament, Barcelona 1989) 17. ... Rad8 (17. ... Rae8 intending ... Re8-e7 and ... c7-c6 was suggested as an improvement for Black by Yasser Seirawan) 18. b3 c6 19. dxc6 bxc6 20. Nf5! gxf5 21. Rxg7+! Kxg7 22. Rg1+ Kf7 23. Dh5+ Ke6 24. Qxf5+ Kf7 25. Qh5+ Ke6 26. Qf5+ Kf7 27. Ng5+ Ke8 28. Ne6 Rf7 29. Rg7! Rc8 30. Rxf7 Kxf7 31. Ng5+ Ke7 32. Qxh7+ Kd8 33. Qh8+ Kc7 34. Qxf6 Re8 35. h4 Nc5 36. h5 Ne6 37. h6+− Karpov – Velimirović, 6th “Solidarity” International Tournament, Skopje 1976. Instead, 13. Nh3!? may be interesting and worth further experimentation, as after 13. ... Nxb2!? 14. Rab1 Nc4 15. Ng5! h6 16. Rbg1! Na6 (16. ... hxg5 17. Qxg5 followed by h2-h4-h5 would give White an irresistible attack) 17. Ne6! Black ended up in big trouble, even if a draw was finally certified at 362nd move (!), Stockfish – Leela Chess Zero, Top Engine Championship Season 14 – Superfinal, match game 86, February 21, 2019. 13. ... f5 14. h4 fxe4 15. Nxe4 c6 16. Qd1 Bd7 17. Kf2!? This and the next move are hard to share with common mortals, as White willingly enters a “cage” which would scare any ordinary human being! 17. ... Bf5 18. Ng3!? Nxb2 19. Qb3 Nd3+ 20. Kg2 Nc5 21. Qd1 Bd7 22. h5 Nba6 23. Rc1 Rf6 24. N1e2 Raf8 25. h6 Bh8 26. Rf1

26. ... g5! 27. Kg1 Rxh6 28. Ne4 Rf7 29. N2c3 Rg6 30. dxc6 Bxc6 31. Rc2 Bg7! Both Black’s Bishops finally come into play. 32. Rd2 Bf8 33. Nxd6 Rf4 34. Ne2! Probably the only move! 34. ... Ba4 35. Qe1 Bxd6 36. Nxf4 gxf4+ 37. Kh1 Bc7! 38. Rh2!? 38. Qh4 Ne6 39. Rg2 Bc6 40. Qf6 Nac5 41. Rxg6+ hxg6 42. Qxg6+ Kf8 43. Qh7 Bd6 44. Rg1 Bxf3+ 45. Kh2 Ke8 46. Rg8+ Bf8 47. Qf5 Ke7 48. Qxe5 Be4 may finally produce a similar ending, but on the whole — and from a human standpoint — that seems a little more defensible. 38. ... Nd7 39. Rg1 Bc6 40. Rxg6+ hxg6 41. Qh4 Bxf3+ 42. Kg1 Bb6+ 43. Kf1 Bh5 44. Qe7 Nac5 45. Rf2. 45. Rd2 e4 46. Rxd7 Nxd7 47. Qxd7?? e3 just loses outright. 45. ... Nf8! 46. Qxe5 Nfe6 47. a4 Bc7 48. Qd5 Bg4 49. Rc2 Bh3+ 50. Ke2 b6 51. Qa8+ Kf7 52. Qxa7 Kf6 53. a5 Bf5 54. Rxc5 bxc5 55. Qa8 Bg4+ 56. Kf1 f3 57. Qh8+ Kg5 58. a6 Bg3 59. a7 Bf5 60. Qh1 Bd3+ 61. Kg1 Nd4 62. Qh2 Bxh2+ 63. Kf2 Kf4 64. Ke1 0 : 1.

Behind the Screens

Stockfish – Leela Chess Zero

Top Chess Engine Championship Season 14 – Superfinal; match game 66; tcec-chess.com, February 17, 2019

Queen’s Indian Defence E15

1. d4 Nf6 2. c4 e6 3. Nf3 b6 4. g3 Ba6 5. b3 d5 6. Bg2 dxc4 7. Ne5 Bb4+ 8. Kf1 Bd6 9. Nxc4 Nd5 10. Bb2 Nc6 11. h4 f5 12. Nbd2 0-0 13. Kg1!? This could be an improvement over 13. Bf3 Be7 14. Kg2 Bb7 15. Rc1 Bf6 16. e3 Qd7 17. Qe2 Rae8 18. a3 Kh8 19. h5 Qf7 20. b4 a6 21. Ne5 Nxe5 22. dxe5 Be7 23. Nb3 Rc8 24. Bd4 Kg8 25. Rhd1 g5 26. hxg6 hxg6 27. Rh1 g5 28. Kg1 Kg7 29. Bh5 Rh8 30. Bf3?? (30. e4! would have won material for White) 30. ... g4! 31. Bg2 Rxh1+ 32. Bxh1 Rh8 with irresistible attack, Ostermeyer – Lau, Solingen 1986. 13. ... b5 14. Nxd6 cxd6 15. e4! Stockfish’s straightforward strategy proves to be quite effective. 15. ... fxe4 16. Nxe4 Qd7 17. Ng5! h6 18. Qg4 Rf5. Not 18. ... hxg5? because of 19. Bxd5 Bc8 20. Bg2 getting an easy and overwhelming attack for free. Likewise after 18. ... Bc8 19. Re1! hxg5 20. hxg5 Qf7 21. f4! White’s attack continues vehemently. 19. Re1! Nf6. Probably Black had nothing better than 19. ... hxg5 20. Qxf5! exf5 21. Bxd5+ Kh7 22. hxg5+ Kg6 23. Re6+ Qxe6 (23. ... Kxg5?? 24. f4+ Kg4 25. Rg6#) 24. Bxe6 Nb4 25. d5 remaining with a Pawn down and an inferior but possibly tenable position. 20. Qe2 Re8 21. Ne4! Stockfish doesn’t distract its Knight with the capture of the e6-Pawn. 21. ... Nd5 22. Bh3! Rf7 23. Bg4! With the threat of Bg4-h5. 23. ... Rfe7 24. Rh2! Qd8 25. f3 Nb8 26. Qc2! White again renews the siege on Black’s castle. 26. ... Bc8 27. Ng5! The Knight is obviously taboo. 27. ... Nf6 28. Bh5! Rf8. Not 20. ... Nxh5?? because of 21. Qh7+ Kf8 22. Qh8#. 29. Bg6. It’s not yet the final destination of the White Bishop’s long journey. 29. ... Na6 30. Qd2 b4!? Black dares a desperate Pawn sacrifice in the vain hope of distracting White from its methodical Kingside attack. 31. g4 Nc7 32. Qxb4 Nfd5 33. Bh7+ Kh8 34. Qd2 Nf4 35. Bb1! Ba6 36. Nh7! Rff7 37. g5 Nh5 38. gxh6 gxh6. 38. ... Rxf3 39. Ng5 was hardly any better at all. 39. d5+ e5 40. Qxh6 Rxh7

41. Rxe5! An elegant pointe finishes the game. 41. ... Rg7+. If 41. ... dxe5 then 42. Bxe5+ Kg8 43. Bxh7+ Rxh7 44. Rg2+ with mate in four moves. If, instead, 41. ... Rxh6 then 42. Rxh5+ possibly transposing into the game. 42. Rg2 Rxh6 43. Rxh5 Ne8. Or 43. ... Rxh5 44. Bxg7+ Kg8 45. Bf6+ and finis. 44. Bxg7+ Nxg7 45. Rxh6+ Kg8 46. Rh7 Qb6+ 47. Kh1 Kf8 48. Rgxg7 Qf2 49. Be4 Qe1+ 50. Rg1 Qe3 51. Rh5 Ke7 52. Rg7+ Kf6 53. Rg6+ Kf7 54. Rh7+ Kf8 55. Rf6+ Kg8 56. Re6! Qe1+ 57. Kh2 Qf2+ 58. Kh3 Bc8 59. Rc7! Qf1+ 60. Kg4 Bxe6+ 61. dxe6 Qg1+ 62. Kh5 Qg3 63. Rf7 Qe5+ 64. Bf5 Qd5 65. Kg5 Qd2+ 66. f4 Qf2 67. Bh7+ Kh8 1 : 0.

劉勃麟 (Liú Bólín), Screens in Rest, 2017. Photo © 劉勃麟 (Liú Bólín).