g15713: Could White have won rook endgame earlier?
E. 1
White to move. Last: 47...Rxb5
 click for larger viewAfter running a 60-minute analysis, Stockfish came up with: 1) +1.30 (48 ply) 48.Re7 Rb6 49.Rc7 h5 50.Rxc5 h4 51.Rc8 Rb5 52.d6 Rd5 53.Rc4 h3 54.Rh4 Rxd6 55.Rxh3 Rc6+ 56.Kd2 Rb6 57.b3 Kf5 58.Kc3 Rc6+ 59.Kb2 Rd6 60.Rc3 Ke5 61.Rc2 Rb6 62.Rc4 Rd6 63.Kc3 Rd1 64.b4 Rb1 65.Rc5+ Ke6 66.Rc6+ Ke5 67.Ra6 Rf1 68.Ra2 Kd5 69.Re2 Kd6 70.Kc4 f5 71.Kb5 Kc7 72.Rc2+ Kb7 73.Kc5 f4 74.Kd5 Rh1 75.Rc4 Rh4 76.Ke5 Rh5+ 77.Ke4 Kb6 78.Rc5 Rh4 79.f3 Rh1 80.Kxf4 2) =0.00 (47 ply) 48.d6 Rb6 49.b3 h5 50.Rd8 Kg7 51.Kc4 h4 52.d7 Rd6 53.Kxc5 Rd1 54.Re8 Rxd7 55.Re4 Rd3 56.b4 Rc3+ 57.Kd5 Rd3+ 58.Kc4 Rh3 59.Re7+ Kg6 60.Re1 Kf5 61.b5 Rf3 62.b6 Rxf2 63.Rh1 Rb2 64.Rxh4 Rxb6 3) =0.00 (47 ply) 48.Rc7 c4 49.d6 Rb3+ 50.Kxc4 Rxb2 51.Kd5 Rd2+ 52.Kc6 Rc2+ 53.Kb7 Rxf2 54.d7 Rd2 55.Kc6 Rc2+ 56.Kb5 Rb2+ 57.Kc6 Rc2+ I was happy as line (1) looked promising for White after 55.Rxh3 E. 1.1
 click for larger view55...Rc6+! 56.Kd2 Rb6! 57.b3 and FinalGen says now 57...Kf5? loses since
58.Kc3! Rc6+ 59.Kb2! White wins
E. 1.2
 click for larger viewSample line from FinalGen, White wins in 41 moves: 1...Rd6 2. Rc3 Ke5 3. Rc2 f5 4. b4 Rd3 5. Kc1 Ra3 6. Rd2 Ra4 7. Rb2! Kd6 8. Rb3 Kc6 9. Kb2! f4 10. Kc3 Ra2 11. Rb2 Ra1 12. b5+ Kb7 13. Kd4 Ra3 14. b6 Kb8 15. b7 f3 16. Ke5 Ra5+ 17. Kf4 Ra3 18. Kg4 Rd3 19. Rb5 Ra3 20. Rf5 Kxb7 21. Rxf3 Ra2 22. Rb3+ Kc6 23. f4! Kd7 24. Re3! etc. However, Black can draw !
Going back to E. 1.1
 click for larger viewReran Stockfish for 60 minutes from this position: 1) =0.00 (51 ply) 57...f5 58.Rd3 f4 59.Kc3 Kg5 60.Kc4 Kg4 61.Kc5 Rb8 62.f3+ Kg3 63.b4 Rc8+ 64.Kb5 Rb8+ 65.Kc4 Rc8+ 66.Kd4 Rd8+ 67.Kc4 Rxd3 68.Kxd3 2) =0.00 (51 ply) 57...Kg5 58.Rg3+ Kf4 59.Kc3 Rc6+ 60.Kd4 Rc2 61.b4 Rxf2 62.Rg1 Kf3 63.b5 f5 64.Rb1 Rd2+ 65.Ke5 f4 66.b6 Rd8 67.b7 Kg3 68.b8=Q Rxb8 3) +1.00 (50 ply) 57...Kf5 58.Kc3 Rc6+ 59.Kb2 Rd6 60.Rc3 Ke5 61.Rc4 f5 62.Kc3 Rh6 63.Rd4 Rc6+ 64.Kd3 f4 65.f3 Rc1 66.Re4+ Kf5 67.Rc4 Rd1+ 68.Kc2 Rf1 69.Rc3 Rf2+ 70.Kc1 Ke5 71.Rd3 Ra2 72.Rd2 Ra8 73.Kb2 Rb8 74.Rd7 Rb5 75.Rd8 Rb7 76.Re8+ Kf5 77.Rc8 Ke5 78.Rc4 Rg7 79.Re4+ Kd5 80.Rxf4 Ke5 81.Re4+ Kd5 82.Kc3 Rh7 83.b4 Rh3 84.Rd4+ Kc6 85.Rc4+ Kb6 Thus 57...Kg5 or f5 draws!
Bottom line, there is no White win in the rook ending as long as Black defends accurately. Game continuation went instead of 48.Re7:
48. Rc7 h5 49. d6 Rb8 50. Rxc5 Rd8 51. Rd5 h4 52. Kc4 Kf7 53. Kc5 Ke6 54. Rd4 Rc8+ 55. Kb6 Kd7 56. Rxh4 Rc6+ 57. Ka5 Rc2 58. b4 Kxd6 59. f3 Rc3 60. f4 Ra3+ 61. Kb6 Ke6 62. Rh5 Rf3 63. f5+ Ke5 64. b5 Kf4 65. Kc6 Kg4 66. Rh1 Rc3+ 67. Kd5 Kxf5 68. Rb1 Rd3+ 69. Kc6 Rd8 70. b6 Kg4?? (70...Ke4! draws) 71. b7 f5 72. b8=Q Rxb8 73. Rxb8 f4 74. Kd5 f3 75. Ke4 f2 76. Rf8 Kg3 77. Ke3 1-0 |