ryspi82 vs Alifabi68

How it swung

The one slip

52...♖b2+ cost 12.0 pawns. ♖h1# would have held it.

There was mate on the board here. 52...♖h1# is it.

The score

1. 1. e4 e5
2. 2. Qh5 Nc6
3. 3. d4 g6
4. 4. Qg5 Be7
5. 5. Qe3 exd4
6. 6. Qd3 Nf6
7. 7. c3 Bc5
8. 8. b4 Ne5
9. 9. Qd2 Nxe4
10. 10. Qf4 d5
11. 11. Qxe5+ Be7
12. 12. Qxh8+ Bf8
13. 13. Qe5+ Be6
14. 14. Qxd4 Qh4
15. 15. g3 Qg4
16. 16. f3 Qf5
17. 17. g4 Qf6
18. 18. g5 Qf5
19. 19. Bh3 c5
20. 20. bxc5 Bxc5
21. 21. Qh8+ Bf8
22. 22. Bxf5 Bxf5
23. 23. Qe5+ Be6
24. 24. fxe4 dxe4
25. 25. Qxe4 O-O-O
26. 26. c4 Bb4+
27. 27. Nd2 Re8
28. 28. a3 Bc3
29. 29. Bb2 Bxb2
30. 30. Ra2 Bc1
31. 31. Qh4 Bxc4+
32. 32. Kd1 Bxa2
33. 33. Kxc1 Re3
34. 34. Nc4 Rc3+
35. 35. Kb2 Rxc4
36. 36. Kxa2 Rxh4
37. 37. Nf3 Rh3
38. 38. Ne5 a5
39. 39. Nxf7 b5
40. 40. Nd6+ Kd7
41. 41. Nxb5 h5
42. 42. Rd1+ Kc6
43. 43. Nd4+ Kc5
44. 44. Nb3+ Kc4
45. 45. Nxa5+ Kb5
46. 46. Rd5+ Kb6
47. 47. Nc4+ Kc6
48. 48. Rd6+ Kc5
49. 49. Rxg6 Kxc4
50. 50. Rh6 Rxh2+
51. 51. Kb1 Kb3
52. 52. g6 Rb2+
53. 53. Kc1 Rc2+
54. 54. Kd1 Kc3
55. 55. g7 Rg2
56. 56. Rh7 h4
57. 57. g8=Q Rxg8
58. 58. Rxh4 Rg1+
59. 59. Ke2 Ra1
60. 60. Rh3+ Kd4
61. 61. Rd3+ Kc4
62. 62. Kd2 Ra2+
63. 63. Ke3 Rh2
64. 64. a4 Rh3+
65. 65. Kd2 Rxd3+
66. 66. Kc2 Rc3+
67. 67. Kd2 Ra3
68. 68. Kc2 Rxa4
69. 69. Kd2 Ra3
70. 70. Ke2 Kd4
71. 71. Kd2 Rc3
72. 72. Ke2 Rc2+
73. 73. Kf3 Rc5
74. 74. Kf4 Re5
75. 75. Kg4 Ke4
76. 76. Kg3 Rf5
77. 77. Kg4 Rf4+
78. 78. Kg5 Rf5+
79. 79. Kg6 Kf4
80. 80. Kg7 Kg5
81. 81. Kh7 Rf6
82. 82. Kg7 Kf5
83. 83. Kg8 Kg6
84. 84. Kh8 Rf8#