Nibble

Leinier Domínguez Pérez – Magnus Carlsen

Champions Chess Tour 2021; 3rd stage; Opera Euro Rapid; Prelims Tournament; time control: 15 minutes plus 10 seconds per move; chess24.com, February 6, 2021

Sicilian Defence B75

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 a6 8. Qd2 h5 9. Bc4 Nbd7 10. 0-0-0 b5 11. Bb3 Nc5 12. Kb1 Bb7

13. Rhe1. It may be interesting to note that after 13. Nd5 a draw was agreed upon in Korneev – Antón Guijarro, 21st Torneo Magistral Internacional de Elgóibar, Elgóibar 2011. An exemplary game, instead, is mentioned by many pre-computer theoreticians, viz., 13. Qf2 Qb8 14. h3 Nxb3 15. Nxb3 b4 16. Na4 a5 17. g4 Nd7 18. Bd4 e5 19. Be3 Qc7 20. Nb6 Nxb6 21. Bxb6 Qd7 22. Nc5 Qc6 23. Nxb7 Qxb7 24. gxh5+− Honfi – Bilek, 21st Hungarian Chess Championship, Budapest 1965 — but Black’s move 19 is a grave error (he ought to have played 19. ... Bc6). Maybe International Master Thomas Rendle is right in assuming that “Kc1-b1 is often a key move in the Sicilian, unfortunately here White missed the strong follow-up 13. Nf5! (now ... Nc5xb3 isn’t check) with the idea of Be3xc5 and Qd2-g5”. 13. ... Rc8. Yet an extra nibble (half a byte) of theory: 13. ... Nxb3 ½ : ½ Narayanan – Jones, 82th Hastings International Chess Congress, Hastings 2006. 14. Bg5 0-0 15. Nd5 e6 16. Nxf6+ Bxf6 17. h4 Bxg5 18. hxg5 Kg7 19. Qe3 Qc7 20. Rd2 b4 21. Red1 Rfd8 22. Qf4 Qe7 23. Ne2 a5 24. e5 d5 25. g4 hxg4 26. Qf6+ Qxf6 27. gxf6+ Kh6? Suddenly switching to the climax. It will be immediately clear why it was necessary for Black to play 27. ... Kf8.

28. Rh1+? Domínguez Pérez apparently misses an unrepeatable opportunity here, viz., 28. Rd4!! (Δ 29. Rh1+ Kg5 30. f4+ Kf5 31. Ng3#) 28. ... gxf3 29. Rg4! Kh5 30. Rg3 g5 31. Nf4+! Kh4 32. Rdg1! gxf4 33. Rg7 followed by mate. 28. ... Kg5 29. f4+ Kf5 30. Rf1 g5 31. Nd4+? 31. Ng3+! Kg6 would likely transpose to the game, since now with 31. ... Ke4! 32. fxg5 Kxe5−+ Black might have written another story. 31. ... Kg6? 32. f5+ exf5 33. Nxf5 g3 34. Rg2. 34. Nxg3 Ne4 can very well transpose to the game. 34. ... Ne4 35. Nxg3 Re8 36. Nxe4 dxe4

37. e6 fxe6. 37. ... e3 38. exf7 Re5 was probably better. 38. f7 Rf8 39. Bxe6 Rc5 40. Rg3? 40. Kc1! would have saved a vital tempo, making Black’s task much harder. Now Carlsen, thanks to back rank “ghostmates”, succeeds without any difficulty in liquidating to a winning ending, even though, as they say, there’s nothing more difficult than winning a won game. 40. ... Re5 41. Bg4 e3 42. Kc1 Rxf7 43. Rxf7 Kxf7 44. Kd1 Kf6 45. Ke1 Bd5 46. a3 bxa3 47. bxa3 Be4 48. Rxe3 Bxc2 49. Kd2 Rxe3 50. Kxe3 Ke5 51. Bf3 Bf5 52. Bc6 Kd6 53. Bf3 Kc5 54. Be2 Bg6 55. Bf1 Bh5 56. Ke4 Bd1 57. Ke3 g4 58. Ba6 Bf3 59. Bf1 Bc6 60. Kf4

60. ... Kd4? 60. ... Bd7, 60. ... Bb5, and 60. ... Bf3 are tablebase wins. 61. Kxg4 Kc3 62. Kf5 Kb2

63. Ke5? 63. Be2 and 63. Kf4 are tablebase draws. 63. ... Kxa3 64. Kd6 (64. Be2 Kb4 65. Bd1 Ba4 66. Bf3 Bb5 67. Bd1 Bc4 68. Bc2 Bb3−+) 64. ... Be8 65. Kc5 a4 66. Bc4 Kb2 67. Kb4 a3 68. Bd5 Bg6 69. Be6 Bb1 70. Bd5 Ba2 71. Be4 Bf7 72. Bb1 Bb3 0 : 1.