Test Position 31.Qh8!

[acase]

In this position, the White Queen moves to h8 so White can bring his rook down to h7 with check. This will be difficult for some engines, and easy for others I would suspect. this position is based on the ERET 84 position after making a few moves..

[d]4rn2/1r2pk2/1p1R1pp1/p1q3B1/2b1P1PQ/2P2P2/P3B1KR/8 w - - 0 31

[elcabesa]

I'm not a big chess player, but what white cha achieve after Qh8! ? I let Stockfish and Vajolet search a lot but cannot din anython but draw

[zullil]

In this position, the White Queen moves to h8 so White can bring his rook down to h7 with check. This will be difficult for some engines, and easy for others I would suspect. this position is based on the ERET 84 position after making a few moves..

[d]4rn2/1r2pk2/1p1R1pp1/p1q3B1/2b1P1PQ/2P2P2/P3B1KR/8 w - - 0 31

Old Critter-1.6a takes a bit to favor Qh8 over Be3, but then sticks with the former:

27/87 33:14 17525M 8788K +1.06 Qh8 fxg5 Rh7+ Nxh7 Qxh7+ Kf8 Qh6+ Kf7 Qxg6+ Kf8 Rc6 Bxe2 Qh6+ Kf7 Qh5+ Kf8 Qh8+ Kf7 Qh7+ Kf8 Rxc5 bxc5 Qf5+ Kg7 Qxg5+ Kf8 Qf5+ Kg7 Qe5+ Kf8 Qh8+ Kf7 Qh7+ Ke6 Qh6+ Kf7 e5 Rf8 e6+ Ke8 Qh5+ Kd8 Qf7 Re8 Qf5 Rg8 Qxc5 Bb5 a4 Be8 g5 Rb2+ Kg3 Rd2 f4 Rb2 Qxa5+ Kc8 Qd5 Rf8 a5 Kc7 Qc5+ Kd8

[zullil]

I'm not a big chess player, but what white cha achieve after Qh8! ? I let Stockfish and Vajolet search a lot but cannot din anython but draw

+3.31 31. Qh8 fxg5 32. Rh7+ Nxh7 33. Qxh7+ Kf8 34. Qh6+ Kf7 35. Qxg6+ Kf8 36. Qh6+ Kf7 37. Rc6 Bxe2 38. Qh7+ Kf8 39. Rxc5 bxc5 40. Qf5+ Kg7 41. Qxg5+ Kf8 42. Qf5+ Kg7 43. Qe5+ Kf8 44. Qh8+ Kf7 45. Qh5+ Kf8 46. e5 Rb2 47. Qh8+ Kf7 48. Qh7+ Kf8 49. Kg3 e6 50. f4 Bc4 51. f5 exf5 52. gxf5 Re7 53. Qh8+ Bg8 54. Qf6+ Ke8 55. Qc6+ Kd8 56. Qd6+ Ke8 57. e6 Rb1 58. Qc6+ Kf8 59. Qc8+ Kg7 60. Qxc5 Kf6 61. Qd4+ Kxf5 62. Qd3+ Kf6 63. Qxb1 Rg7+ 64. Kf3 Bxe6 65. Qb6 Rg5 66. Qd8+ Kg6 67. a4 Rd5 68. Qe7 Kf5 69. Qf8+ Kg6 70. Ke4 Rg5 71. Qd8 Rf5 72. Kd4 Rg5 73. Qe8+ Kf6 74. Qf8+ Bf7 75. Qd6+ Be6 76. Qf4+ Kg6 77. Ke3 Bb3 78. Qe4+ Kf6 (depth 50, 0:05:59)

[S.Taylor]

In this position, the White Queen moves to h8 so White can bring his rook down to h7 with check. This will be difficult for some engines, and easy for others I would suspect. this position is based on the ERET 84 position after making a few moves..

[d]4rn2/1r2pk2/1p1R1pp1/p1q3B1/2b1P1PQ/2P2P2/P3B1KR/8 w - - 0 31

Qh8 looks the easiest move to the human eye. The only reply for black seems to be fxg5. And it's only after that, that calculation is needed.

[zullil]

I'm not a big chess player, but what white cha achieve after Qh8! ? I let Stockfish and Vajolet search a lot but cannot din anython but draw

+3.31 31. Qh8 fxg5 32. Rh7+ Nxh7 33. Qxh7+ Kf8 34. Qh6+ Kf7 35. Qxg6+ Kf8 36. Qh6+ Kf7 37. Rc6 Bxe2 38. Qh7+ Kf8 39. Rxc5 bxc5 40. Qf5+ Kg7 41. Qxg5+ Kf8 42. Qf5+ Kg7 43. Qe5+ Kf8 44. Qh8+ Kf7 45. Qh5+ Kf8 46. e5 Rb2 47. Qh8+ Kf7 48. Qh7+ Kf8 49. Kg3 e6 50. f4 Bc4 51. f5 exf5 52. gxf5 Re7 53. Qh8+ Bg8 54. Qf6+ Ke8 55. Qc6+ Kd8 56. Qd6+ Ke8 57. e6 Rb1 58. Qc6+ Kf8 59. Qc8+ Kg7 60. Qxc5 Kf6 61. Qd4+ Kxf5 62. Qd3+ Kf6 63. Qxb1 Rg7+ 64. Kf3 Bxe6 65. Qb6 Rg5 66. Qd8+ Kg6 67. a4 Rd5 68. Qe7 Kf5 69. Qf8+ Kg6 70. Ke4 Rg5 71. Qd8 Rf5 72. Kd4 Rg5 73. Qe8+ Kf6 74. Qf8+ Bf7 75. Qd6+ Be6 76. Qf4+ Kg6 77. Ke3 Bb3 78. Qe4+ Kf6 (depth 50, 0:05:59)

+4.11 31. Qh8 fxg5 32. Rh7+ Nxh7 33. Qxh7+ Kf8 34. Qh6+ Kf7 35. Qxg6+ Kf8 36. Qh6+ Kf7 37. Rc6 Bxe2 38. Qh7+ Kf8 39. Rxc5 bxc5 40. Qf5+ Kg7 41. Qxg5+ Kf8 42. Qf5+ Kg7 43. Qe5+ Kf8 44. Qh8+ Kf7 45. Qh5+ Kf8 46. e5 Rb6 47. Qh8+ Kf7 48. Qh7+ Kf8 49. g5 Bc4 50. g6 Reb8 51. g7+ Ke8 52. g8=Q+ Bxg8 53. Qxg8+ Kd7 54. Qd5+ Ke8 55. f4 e6 56. Qxc5 Kd7 57. Qxa5 Rc6 58. f5 exf5 59. Qd5+ Kc7 60. Qf7+ Kb6 61. e6 Rxc3 62. Qf6 Rcc8 63. Qd4+ Kb7 64. Qd5+ Ka6 65. e7 Kb6 66. Qd6+ Kb7 67. Qd7+ Ka6 68. Kf3 Re8 69. Kf4 Rg8 70. a4 Rge8 71. Qxf5 Kb6 72. Qb5+ Kc7 73. Qe5+ Kc6 74. Qe6+ Kb7 75. Kg5 Ka7 76. Qd7+ Kb6 77. Kg6 Rec8 78. Qb5+ Kc7 79. Qe5+ Kb6 80. Kf7 Rg8 81. Qb5+ Ka7 82. Qc5+ Ka6 83. Kf6 Rgc8 84. Qe5 Ka7 85. Qd4+ Ka6 86. Ke6 Rc6+ 87. Kf5 Rcc8 88. Qe5 Rh8 89. Qd6+ Ka5 90. Qd7 Ka6 91. Kf6 Kb6 92. Qb5+ Kc7 93. Qc5+ Kb7 (depth 65, 3:32:51)

[MikeB]

In this position, the White Queen moves to h8 so White can bring his rook down to h7 with check. This will be difficult for some engines, and easy for others I would suspect. this position is based on the ERET 84 position after making a few moves..

[d]4rn2/1r2pk2/1p1R1pp1/p1q3B1/2b1P1PQ/2P2P2/P3B1KR/8 w - - 0 31

McCain-X3 does get it eventually , after a one false start.

https://github.com/MichaelB7/Stockfish/releases/tag/X3

Code: Select all

dep	score	nodes	time	(not shown:  tbhits	knps	seldep)
 46	+2.33!	21.4G	14:30.15	Qh8! 
 46	+2.21?	21.1G	14:20.40	Qh8 fxg5? 
 45	+2.26 	17.6G	12:07.51	Qh8 fxg5 Rh7+ Nxh7 Qxh7+ Kf8 Qh6+ Kf7 Qxg6+ Kf8 Qh6+ Kf7 Rc6 Bxe2 Qh7+ Kf8 Rxc5 bxc5 Qf5+ Kg7 Qxg5+ Kf8 Qf5+ Kg7 Qe5+ Kf8 Qh8+ Kf7 Qh5+ Kf8 e5 Rb2 Qh8+ Kf7 Qh7+ Kf8 Kg3 e6 f4 Bxg4 Kxg4 Re7 Qh8+ Kf7 a4 Rg2+ Kf3 Rg1 Ke4 Rf1 Ke3 c 
 44	+2.14 	16.1G	11:10.51	Qh8 fxg5 Rh7+ Nxh7 Qxh7+ Kf8 Qh6+ Kf7 Qxg6+ Kf8 Qh6+ Kf7 Rc6 Bxe2 Qh7+ Kf8 Rxc5 bxc5 Qf5+ Kg7 Qxg5+ Kf8 Qf5+ Kg7 Qe5+ Kf8 Qh8+ Kf7 Qh5+ Kf8 e5 Rb6 Qf5+ Kg7 e6 Bxf3+ Kg3 Rg8 Qf7+ Kh8 Kxf3 Rg7 Qf5 Kg8 a4 Rb8 Kg3 Rf8 Qxc5 Rf6 Qxa5 
 44	+1.99!	15.5G	10:44.13	Qh8! 
 44	+1.88?	14.9G	10:21.62	Qh8 fxg5? 
 43	+1.93 	14.6G	10:10.30	Qh8 fxg5 Rh7+ Nxh7 Qxh7+ Kf8 Qh6+ Kf7 Qxg6+ Kf8 Qh6+ Kf7 Rc6 Bxe2 Qh7+ Kf8 Rxc5 bxc5 Qf5+ Kg7 Qxg5+ Kf8 Qf5+ Kg7 Qe5+ Kf8 Qh8+ Kf7 Qh5+ Kf8 e5 Rb2 Qh8+ Kf7 Qh7+ Kf8 Kg3 e6 f4 Bc4 f5 exf5 gxf5 a4 e6 Rxe6 fxe6 Bxe6 a3 Bb3 Qe4 c4  
 43	+1.73!	14.3G	9:58.63	Qh8! 
 43	+1.66?	14.0G	9:44.60	Qh8 fxg5? 
 43	+1.71?	13.5G	9:25.81	Qh8 fxg5? 
 42	+1.76 	13.4G	9:22.45	Qh8 fxg5 Rh7+ Nxh7 Qxh7+ Kf8 Qh6+ Kf7 Qxg6+ Kf8 Qh6+ Kf7 Rc6 Bxe2 Qh7+ Kf8 Rxc5 bxc5 Qf5+ Kg7 Qxg5+ Kf8 Qf5+ Kg7 Qe5+ Kf8 Qh8+ Kf7 Qh5+ Kf8 e5 Rb2 Qh8+ Kf7 Qh7+ Kf8 Kg3 e6 f4 Bf1 f5 exf5 gxf5 Bc4 Qh6+ Kf7 Qg6+ Kf8 f6 Rxe5 Qg7+ K 
 42	+1.74!	13.4G	9:19.96	Qh8! 
 42	+1.55!	12.7G	8:54.31	Qh8! 
 42	+1.45?	12.4G	8:40.52	Qh8 fxg5? 
 41	+1.50 	12.4G	8:39.03	Qh8 fxg5 Rh7+ Nxh7 Qxh7+ Kf8 Qh6+ Kf7 Qxg6+ Kf8 Qh6+ Kf7 Rc6 Bxe2 Qh7+ Kf8 Rxc5 bxc5 Qf5+ Kg7 Qxg5+ Kf8 Qf5+ Kg7 Qe5+ Kf8 Qh8+ Kf7 Qh5+ Kf8 e5 Rb2 Qh8+ Kf7 Qh7+ Kf8 Kg3 e6 f4 Bxg4 Kxg4 Re7 Qh8+ Kf7 a4 Rg2+ Kf3 Rg1 Ke4 Rf1 Kd3 Rf 
 41	+1.27!	12.0G	8:26.38	Qh8! 
 41	+1.06!	11.9G	8:20.71	Qh8! 
 41	+1.00?	11.8G	8:15.56	Qh8 fxg5? 
 41	+1.05?	11.8G	8:13.91	Qh8 fxg5? 
 40	+1.10 	11.7G	8:12.12	Qh8 fxg5 Rh7+ Nxh7 Qxh7+ Kf8 Qh6+ Kf7 Qxg6+ Kf8 Qh6+ Kf7 Rc6 Bxe2 Qh7+ Kf8 Rxc5 bxc5 Qf5+ Kg7 Qxg5+ Kf8 Qf5+ Kg7 Qe5+ Kf8 Qh8+ Kf7 Qh5+ Kf8 e5 Rb2 Qh8+ Kf7 Qh7+ Kf8 Kg3 e6 f4 Bxg4 Kxg4 Re7 Qh8+ Kf7 Kf3 a4 Qf6+ Ke8 f5 exf5 e6 Reb 
 40	+0.70!	11.6G	8:05.93	Qh8! 
 40	+0.12!	10.0G	7:01.58	Be3 Qc7! 
 40	+0.15!	10.0G	7:01.44	Qh8! 
 40	+0.28!	10.0G	7:00.92	Qh8! 
 40	+0.30!	10.0G	7:00.41	Qh8! 
 40	+0.48!	9.96G	6:58.41	Qh8! 
 40	+0.30!	8.46G	5:53.88	Be3! 
 40	+0.23?	8.04G	5:36.47	Be3 Qc7? 
 40	+0.31?	7.19G	5:00.02	Be3 Qc7? 
 40	+0.36?	6.84G	4:45.09	Be3 Qc7? 
 39	+0.41 	5.54G	3:50.72	Be3 Qc7 Rd2 Bxe2 Rxe2 Qc4 Kg3 Qxc3 Qh8 Rd7 Bd2 Qe5+ Bf4 Qxf4+ Kxf4 Ne6+ Ke3 Rxh8 Rxh8 Rc7 Rh7+ Ke8 Kd2 Rd7+ Kc1 Rd3 Rb2 Rc3+ Kd1 Rxf3 Rxb6 Ng5 Rh8+ Kf7 e5 fxe5 Rb5 Ke6 Rxa5 Rf4 Ra6+ Kf7 Raa8 Ke6 Rhe8 Rxg4 Ra7 Rg2 a4 Ra2 Rexe7+ K 
 39	+0.46!	5.21G	3:36.89	Be3! 

[Andrew]

Komodo 12.3 and lczero (I tried the 42146 network) both get this quickly (under a minute, 4 threads)

Houdini 6.01 didn't

Andrew