patzer2: For today's Sunday puzzle (19. ?), I correctly guessed the first two moves with 19. Nxe6! fxe6 20. f7+ Ke7. But I failed to pick the strong winning follow-up 21. Rg6! +- (+7.20 @ 29 ply, Stockfish 8) because I thought Black could hold after 21...Rh7 (diagram below).
 click for larger viewHowever, I was wrong. After 21...Rh7 (diagram above), White wins with 22. Nd5+! due to the clever mate-in-two threat 22...exd5? 23. Re6+! Kxe6 (23...Kd8 24. Re8#) 24. exd5#. Instead of 20...Ke7 21. Rg6! +- (+7.20 @ 29 ply, Stockfish 8), Black could have put up more resistance with 20...Kd8, when White maintains a difficult advantage after 20...Kd8 21. Rg1 Rh6 22. Qg3 Ke7 23. Qh4+ Kxf7 24. Qg5 Rf6 25. Be2 Ke7 26. e5 dxe5 27. Rg6 Bb7 28. Rf1 Kd6 29. Rfxf6+ Nxf6 30. Rxf6 Qg7 31. Rg6 Qf7 32. Kb1 Qf4 33. Qg1 Qd4 34. Qf1 Qf4 35. Qh3 Qf7 36. Rg1 Kc7 37. Rf1 Qe8 38. Bxh5 Qd7 39. Bf7 Rd8 40. Bxe6 Qd4 41. Rd1 Qc5 42. Rxd8 Kxd8 43. Qh7 Bc6 44. Qg8 a5 45. Nd5 Bxd5 46. Bxd5 Kc7 +- (+1.70 @ 34 ply, Stockfish 8) P.S.: Black's game starts to go bad after 17...Rb8 allowing 18. Re1 ± (+1.11 @ 28 ply, Stockfish 8). Instead, 17...Qb6 18. Kb1 b4 19. axb4 Qxb4 20. e5 Bb7 21. Qf2 0-0-0 22. Nf3 ⩲ (+0.52 @ 33 ply, Stockfish 8) gives the second player active counter chances. For a possible improvement in this Sicilian Najdorf opening line, instead of 13...Nc5 potentially allowing 14. Rg1 ⩲ (+0.57 @ 30 ply, Stockfish 8), I prefer 13...0-0 = (+0.16 @ 32 ply, Stockfish 8) as in Black's win in D Shailesh vs D Eggleston, 2017. |