A hard endgame (?) study

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Nordlandia
Posts: 2821
Joined: Fri Sep 25, 2015 9:38 pm
Location: Sortland, Norway

Re: A hard endgame (?) study

Post by Nordlandia »

MikeB wrote:if one plays
Ba8 , iSF-Mcb 2.6 will see that there is a tablebase mate in less than 5 minutes, ymmv.

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dep	score	nodes	time	(not shown:  tbhits	knps	seldep)
 46	+128.33 	8.47G	4:31.63	Rc8 Bd5 Bc6 Bxc6 Ra8 Ba4 Re8 Ka3 Ra8 Re6 fxe6 Kb2 Rd8 Kc3 Kf7 Bb5 Rc8+ Kb2 Rd8 Bc6 Kg8 Ka3 Rc8 Bd7 Ra8+ Kb2 Kf7 Bc6 Rd8 Be4 Rd2+ Ka3 Rd1 Bxh7 Kxf6 g8=Q Ke7 Qg3 Ra1+ Kb2 Rd1 Qc7+ Rd7 Qxd7+ Kxd7 
 45	+128.33 	8.45G	4:30.96	Rc8 Bd5 Bc6 Bxc6 Ra8 Ba4 Re8 Ka3 Ra8 Re6 fxe6 Kb2 Rd8 Kc3 Kf7 Bb5 Rc8+ Kb2 Rd8 Bc6 Kg8 Ka3 Rc8 Bd7 Ra8+ Kb2 Kf7 Bc6 Rd8 Be4 Rd2+ Ka3 Rd1 Bxh7 Kxf6 g8=Q Ke7 Qg3 Ra1+ Kb2 Rd1 Qc7+ Rd7 Qxd7+ Kxd7 
 44	+128.33 	8.30G	4:26.59	Rc8 Bd5 Bc6 Bxc6 Ra8 Ba4 Re8 Ka3 Ra8 Re6 fxe6 Kb2 Rd8 Kc3 Kf7 Bb5 Rc8+ Kb2 Rd8 Bc6 Kg8 Ka3 Rc8 Bd7 Ra8+ Kb2 Kf7 Bc6 Rd8 Be4 Rd2+ Ka3 Rd1 Bxh7 Kxf6 g8=Q Ke7 Qg3 Ra1+ Kb2 Rd1 Qc7+ Rd7 Qxd7+ Kxd7 
 43	+128.33 	8.28G	4:26.06	Rc8 Bd5 Bc6 Bxc6 Ra8 Ba4 Re8 Ka3 Ra8 Re6 fxe6 Kb2 Rd8 Kc3 Kf7 Bb5 Rc8+ Kb2 Rd8 Bc6 Kg8 Ka3 Rc8 Bd7 Ra8+ Kb2 Kf7 Bc6 Rd8 Be4 Rd2+ Ka3 Rd1 Bxh7 Kxf6 g8=Q Ke7 Qg3 Ra1+ Kb2 Rd1 Qc7+ Rd7 Qxd7+ Kxd7 
 42	+128.33 	8.25G	4:25.12	Rc8 Bd5 Bc6 Bxc6 Ra8 Ba4 Re8 Ka3 Ra8 Re6 fxe6 Kb2 Rd8 Kc3 Kf7 Bb5 Rc8+ Kb2 Rd8 Bc6 Kg8 Ka3 Rc8 Bd7 Ra8+ Kb2 Kf7 Bc6 Rd8 Be4 Rd2+ Ka3 Rd1 Bxh7 Kxf6 g8=Q Ke7 Qg3 Ra1+ Kb2 Rd1 Qc7+ Rd7 Qxd7+ Kxd7 
 41	+128.32 	7.94G	4:15.89	Rc8 Bd5 Bc6 Bxc6 Ra8 Ba4 Re8 Ka3 Ra8 Re6 fxe6 Kb2 Rd8 Kc3 Rc8+ Kd4 Kf7 b4 Rd8+ Ke3 Rc8 Kf4 Kxf6 Bc2 Rc4+ Ke3 Rc3+ Bd3 Kf7 Kd2 Ra3 Bxh7 Ke7 g8=Q Ra2+ Kd3 Ra3+ Ke4 Kd7 Bf5 Kc7 Bxe6 Ra7 Qg7+ Kb6 Qxa7+ 
 40	+128.32 	7.94G	4:15.82	Rc8 Bd5 Bc6 Bxc6 Ra8 Ba4 Re8 Ka3 Ra8 Re6 fxe6 Kb2 Rd8 Kc3 Rc8+ Kd4 Kf7 b4 Rd8+ Ke3 Rc8 Kf4 Kxf6 Bc2 Rc4+ Ke3 Rc3+ Bd3 Kf7 Kd2 Ra3 Bxh7 Ke7 g8=Q Ra2+ Kd3 Ra3+ Ke4 Kd7 Bf5 Kc7 Bxe6 Ra7 Qg7+ Kb6 Qxa7+ 
 40	+116.33?	6.60G	3:30.62	Re5 Bh1? 
 40	+106.77!	6.58G	3:29.96	Re5!
Michael B: how long does it take McBrain to solve this study if you doesn't play a8=B?
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Vinvin
Posts: 5228
Joined: Thu Mar 09, 2006 9:40 am
Full name: Vincent Lejeune

Re: A hard endgame (?) study

Post by Vinvin »

Nordlandia wrote:Sokolsky - Ravinsky, USSR 1938 (or 1933)

a8=B is supposed to win, however no engine see a breakthrough.

[d]4b1k1/P4pPp/1R3P1P/2r5/8/1P6/1K6/8 w - - 0 0

https://timkr.home.xs4all.nl/chess2/minor.htm
Finally found by SF after 9h57m ! (see last line)
CPU 6*4GHz, 8 GB hash

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Stockfish_170810_x64_modern:
...
 84/95	06:06	 7 490 732k	20 429k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Kb4 Re4+ 30.Kb3 Re3+ 31.Kc4 Ra3 32.Re5 Ra4+ 33.Kc3 Re4 34.Rb5 Re3+ 35.Kc2 Re2+ 36.Kd1 Re8 37.Rc5 Be4 38.Kc1 Bb7 39.Rc7 Rd8 40.Kc2 Bd5 41.Kc3 Bb7 42.Kb3 Re8 43.Rc3 Ba6 44.Rc5 Bb7 45.Kc2 Re2+ 46.Kd1 Re8 47.Kd2
 85/100	06:16	 7 710 549k	20 469k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Kb2 Re2+ 30.Kb3 Re3+ 31.Kc4 Ra3 32.Re5 Ra4+ 33.Kd3 Re4 34.Rc5 Re8 35.Rc4 Rd8+ 36.Kc3 Re8 37.Rd4 Bb7 38.Rd6 Re3+ 39.Kd2 Re8 40.Rd3 Ba6 41.Kc3 Rc8+ 42.Kb4 Rc4+ 43.Ka5 Rc5+ 44.Ka4 Rc4+ 45.Ka3 Rc8 46.Re3 Bb7 47.Kb4 Bd5 48.Kb5 Ba8 49.Re7 Bc6+ 50.Kc4 Bb7+ 51.Kb4
 86/95	06:42	 8 302 066k	20 633k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Kb2 Re2+ 30.Kb3 Re3+ 31.Kc4 Ra3 32.Re5 Ra4+ 33.Kb3 Re4 34.Rb5 Re3+ 35.Kc2 Re2+ 36.Kd1 Re8 37.Rb3 Rd8+ 38.Kc2 Re8 39.Rc3 Rd8 40.Kb2 Re8 41.Rd3 Bd5 42.Ka3 Rc8 43.Kb4 Rc4+ 44.Kb5 Rc8 45.Re3 Ba8 46.Re7 Bc6+ 47.Kc4 Bb7+ 48.Kd3
 87/103	07:04	 8 775 388k	20 677k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Kb2 Re2+ 30.Kb3 Re3+ 31.Kc4 Ra3 32.Re5 Ra4+ 33.Kc3 Re4 34.Rb5 Re3+ 35.Kc2 Re2+ 36.Kd1 Re8 37.Ra5 Bb7 38.Kc2 Bg2 39.Rc5 Bc6 40.Rc3 Rd8 41.Kb2 Re8 42.Rd3 Bd5 43.Ka3 Rc8 44.Kb4 Rc4+ 45.Kb5 Rc8 46.Rxd5 Rc5+ 47.Ka4 Rc4+ 48.Ka3 Rc3+ 49.Kb4 Rc4+ 50.Ka5 Rc5+ 51.Kb4 Rb5+ 52.Kc4
 88/98	07:15	 8 992 353k	20 641k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Kb2 Re2+ 30.Kb3 Re3+ 31.Kc4 Re4+ 32.Kd3 Re8 33.Kd2 Ra8 34.Re5 Bf3 35.Kc3 Rd8 36.Re7 Rc8+ 37.Kb4 Bg2 38.Ka3 Bd5 39.Rc7 Ra8 40.Kb4 Re8 41.Kc5 Bb7 42.Re7 Rc8+ 43.Kd4 Rd8+ 44.Kc3 Bd5 45.Re3 Bb7 46.Re5 Rc8+ 47.Kb2 Bd5 48.Re7 Bc6
 89/101	07:24	 9 168 969k	20 628k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Kb2 Re2+ 30.Kb3 Re3+ 31.Kc4 Ra3 32.Kb4 Ra4+ 33.Kc3 Ra3+ 34.Kd4 Ra4+ 35.Ke3 Ra3+ 36.Kf4 Ra4+ 37.Kg5 Bb7 38.Rc7 Ra3 39.Kf4 Ra5 40.Re7 Ra4+ 41.Ke3 Re4+ 42.Kd3 Bc6 43.Rc7 Re8 44.Kc4 Re4+ 45.Kc3 Re3+ 46.Kb2 Re2+ 47.Ka3 Re8 48.Re7 Rc8 49.Re5 Bg2 50.Kb4 Ba8 51.Ra5
 90/107	08:01	 9 856 743k	20 483k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Kb2 Re2+ 30.Kb3 Re3+ 31.Kc4 Re4+ 32.Kd3 Re8 33.Kd2 Bb7 34.Kc3 Bc6 35.Rc4 Re3+ 36.Kb2 Re2+ 37.Kc1 Re1+ 38.Kd2 Re8 39.Rd4 Bb7 40.Rd3 Bc6 41.Kc3 Rc8 42.Re3 Bb7+ 43.Kd2 Rd8+ 44.Kc1 Bc6 45.Ra3 Bh1 46.Kb2 Rd2+ 47.Kc3 Rd8 48.Ra5 Rc8+ 49.Kb3 Re8 50.Rc5 Bc6 51.Rxc6 Re3+ 52.Ka4 Re4+ 53.Ka5 Re5+ 54.Kb4
 91/100	08:31	 10 455 118k	20 428k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Kb2 Re2+ 30.Kb3 Re3+ 31.Kc4 Re4+ 32.Kd3 Re8 33.Ra5 Be4+ 34.Kc4 Bc6 35.Ra3 Bd5+ 36.Kb4 Re4+ 37.Kc5 Re8 38.Kd4 Bg2 39.Ra5 Re4+ 40.Kd3 Re8 41.Ra3 Bc6 42.Rc3 Bd5 43.Kd2 Bc6 44.Rc5 Bb7 45.Kc1 Bg2 46.Kb2 Bc6 47.Rc2 Rd8 48.Rc3 Re8 49.Rd3 Bd5 50.Ka3 Rc8
 92/102	09:11	 11 234 979k	20 372k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Kb2 Re2+ 30.Kb3 Re3+ 31.Kc4 Re4+ 32.Kd3 Re8 33.Kc2 Re2+ 34.Kd1 Re8 35.Rc3 Ba8 36.Kd2 Bc6 37.Rc5 Bb7 38.Kc1 Bg2 39.Rc3 Rd8 40.Rc4 Bd5 41.Rc7 Be4 42.Re7 Bd5 43.Re3 Bc6 44.Ra3 Bd5 45.Ra5 Rc8+ 46.Kb2 Ba8 47.Ra3 Bb7 48.Rd3 Bd5 49.Rxd5 Rc2+ 50.Ka3 Rc3+ 51.Kb4 Rc4+ 52.Kb5
 93/109	09:14	 11 294 632k	20 364k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Kb2 Re2+ 30.Kb3 Re3+ 31.Kc4 Re4+ 32.Kd3 Re8 33.Kc2 Re2+ 34.Kd1 Re8 35.Rc2 Be4 36.Rc7 Rd8+ 37.Kc1 Bh1 38.Kb2 Rd2+ 39.Kc3 Rd8 40.Kb4 Re8 41.Kb5 Bg2 42.Kc4 Bb7 43.Rc5 Re4+ 44.Kd3 Re8 45.Rc7 Bg2 46.Kc2 Be4+ 47.Kd2 Bd5 48.Re7 Rd8 49.Re5 Bb7+ 50.Kc3 Rc8+ 51.Kd4 Rd8+ 52.Kc4 Ra8 53.Re7 Rd8
 94/115	10:11	 12 489 673k	20 410k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Kb2 Re2+ 30.Kb3 Re3+ 31.Kc4 Re4+ 32.Kd3 Re8 33.Rc3 Bd5 34.Kd4 Rd8 35.Ra3 Ba8+ 36.Kc4 Bb7 37.Re3 Rc8+ 38.Kb3 Bd5+ 39.Kb4 Bb7 40.Rd3 Re8 41.Rd7 Re4+ 42.Kc3 Re3+ 43.Kc4 Re4+ 44.Kd3 Re8 45.Rc7 Bg2 46.Kc2 Be4+ 47.Kd1 Rd8+ 48.Kc1 Bh1 49.Kb2 Rd2+ 50.Kc3 Rd8 51.Kb4 Re8 52.Rc2 Bc6 53.Rxc6 Re4+ 54.Kb3 Re3+ 55.Kb2 Re2+ 56.Kc3 Re3+ 57.Kc4 Re4+ 58.Kd3
 95/106	11:39	 14 138 926k	20 202k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Rc2 Bb7 30.Rc7 Rd8 31.Kb3 Re8 32.Rc4 Bd5 33.Kc3 Re3+ 34.Kb2 Re2+ 35.Kc1 Re8 36.Rc5 Ra8 37.Ra5 Rc8+ 38.Kd2 Rd8 39.Kc2 Rc8+ 40.Kb2 Bb7 41.Re5 Ra8 42.Kb3 Rc8 43.Kb4 Ba8 44.Ra5 Re8 45.Rc5 Bg2 46.Rc7 Bf3 47.Rc4 Ba8 48.Rc3 Bc6 49.Rd3 Ba8 50.Kc4 Bc6 51.Kc3 Rc8 52.Kb4
 96/108	12:34	 15 227 874k	20 187k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Rc2 Bb7 30.Rc7 Rd8 31.Kb3 Re8 32.Rc4 Bd5 33.Kc3 Re3+ 34.Kb2 Re2+ 35.Kc1 Re8 36.Rc5 Ra8 37.Ra5 Rc8+ 38.Kd2 Rd8 39.Kc2 Re8 40.Kb2 Bc6 41.Ra3 Re2+ 42.Kc1 Re1+ 43.Kd2 Re8 44.Ra5 Bb7 45.Rg5 Rd8+ 46.Kc3 Rd5 47.Rg1 Rb5 48.Re1 Rc5+ 49.Kb4 Rc8 50.Re3 Bd5 51.Kb5 Ba8 52.Re2 Bd5 53.Re7 Bc6+ 54.Ka5 Bd5
 97/109	13:59	 17 131 312k	20 413k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Rc2 Bb7 30.Rc7 Rd8 31.Kb3 Re8 32.Rc4 Bd5 33.Kc3 Re3+ 34.Kb2 Re2+ 35.Kc1 Re8 36.Rc5 Ra8 37.Ra5 Rc8+ 38.Kd2 Rd8 39.Kc2 Re8 40.Kb2 Bc6 41.Ra3 Re2+ 42.Kc1 Re1+ 43.Kd2 Re8 44.Rd3 Rc8 45.Kc3 Bg2+ 46.Kb2 Bb7 47.Rd7 Bf3 48.Rc7 Re8 49.Re7 Rc8 50.Ka3 Bd5 51.Rc7 Ra8 52.Kb4 Re8 53.Rc2 Re4+ 54.Kc5 Re8
 98/117	14:25	 17 667 098k	20 408k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Rc2 Bb7 30.Rc7 Rd8 31.Kb3 Re8 32.Rc4 Bd5 33.Kc3 Re3+ 34.Kb2 Re2+ 35.Kc1 Re8 36.Rc5 Ra8 37.Ra5 Rc8+ 38.Kd2 Rd8 39.Kc2 Re8 40.Kb2 Bc6 41.Ra3 Re2+ 42.Kc1 Re1+ 43.Kd2 Re8 44.Rd3 Rc8 45.Re3 Ba8 46.Ra3 Bf3 47.Ra5 Bd5 48.Rb5 Rd8 49.Kc3 Bc6 50.Re5 Bb7 51.Re7 Rc8+ 52.Kb2 Bd5 53.Re2 Rd8 54.Re5 Rc8 55.Rxd5 Rc2+ 56.Kb3 Rc3+ 57.Kb4
 99/116	15:12	 18 583 891k	20 369k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Rc2 Bb7 30.Rc7 Rd8 31.Kb3 Re8 32.Rc4 Bd5 33.Kc3 Re3+ 34.Kb2 Re2+ 35.Kc1 Re8 36.Rc5 Ra8 37.Ra5 Rc8+ 38.Kd2 Rd8 39.Kc2 Re8 40.Kb2 Bc6 41.Ra3 Re2+ 42.Kc1 Re1+ 43.Kd2 Re8 44.Rd3 Rc8 45.Re3 Ba8 46.Ra3 Bf3 47.Ra5 Bd5 48.Rb5 Rd8 49.Kc3 Bc6 50.Re5 Bb7 51.Re7 Rc8+ 52.Kd2 Bc6 53.Rc7 Re8 54.Rxc6 Re2+ 55.Kc3 Re3+ 56.Kd4 Re4+ 57.Kc5
 100/115	17:55	 21 793 736k	20 262k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Rc2 Bb7 30.Rc7 Rd8 31.Kb3 Re8 32.Rc4 Bd5 33.Kc3 Re3+ 34.Kb2 Re2+ 35.Kc1 Re8 36.Rc5 Ra8 37.Ra5 Rc8+ 38.Kd2 Rd8 39.Kc2 Re8 40.Kb2 Bc6 41.Ra3 Re2+ 42.Kc1 Re1+ 43.Kd2 Re8 44.Rd3 Rc8 45.Re3 Ba8 46.Ra3 Bf3 47.Ra5 Bd5 48.Rb5 Rd8 49.Kc3 Bc6 50.Re5 Bb7 51.Re7 Rc8+ 52.Kd2 Bc6 53.Rc7 Re8 54.Rxc6 Rd8+ 55.Kc3 Rd3+ 56.Kc4 Rc3+ 57.Kd4 Rd3+ 58.Kc5
 101/114	19:02	 23 002 462k	20 134k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Rc2 Bb7 30.Rc7 Rd8 31.Kb3 Re8 32.Rc4 Bd5 33.Kc3 Re3+ 34.Kb2 Re2+ 35.Kc1 Re8 36.Rc5 Ra8 37.Ra5 Rc8+ 38.Kd2 Rd8 39.Kc2 Re8 40.Kb2 Bc6 41.Ra3 Re2+ 42.Kc1 Re1+ 43.Kd2 Re8 44.Rd3 Rc8 45.Re3 Ba8 46.Ra3 Bf3 47.Ra5 Bd5 48.Rb5 Rd8 49.Kc3 Bc6 50.Rc5 Re8 51.Rc4 Re3+ 52.Kd2 Re8 53.Rxc6 Re2+ 54.Kc3 Re3+ 55.Kd4 Re4+ 56.Kd5 Re5+ 57.Kd6
 102/117	3:09:50	183 893 692k	16 144k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc5 Bc6 29.Rc2 Bb7 30.Rc7 Rd8 31.Kb3 Re8 32.Rc4 Bd5 33.Kc3 Re3+ 34.Kb2 Re2+ 35.Kc1 Re8 36.Rc5 Ra8 37.Ra5 Rc8+ 38.Kd2 Rd8 39.Kc2 Re8 40.Kb2 Bc6 41.Ra3 Re2+ 42.Kc1 Re1+ 43.Kd2 Re8 44.Rd3 Rc8 45.Re3 Bg2 46.Re7 Bc6 47.Rc7 Re8 48.Rd7 Bb7 49.Kd3 Bc6 50.Kd4 Rc8 51.Rc7 Re8 52.Rxc6 Rd8+ 53.Ke5 Re8+ 54.Kd6 Rd8+ 55.Kc5 Rd5+ 56.Kb4 Rd4+ 57.Kc3 Rd3+ 58.Kc4
 103/117	3:09:55	183 964 679k	16 144k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc4 Bd5 29.Kb2 Re2+ 30.Kb1 Re1+ 31.Kc2 Re2+ 32.Kd1 Re8 33.Rc5 Bc6 34.Kc1 Re1+ 35.Kb2 Re2+ 36.Kb1 Re1+ 37.Kc2 Re2+ 38.Kb3 Re3+ 39.Kc4 Re4+ 40.Kd3 Re8 41.Kd2 Bg2 42.Rc7 Bd5 43.Rc3 Bc6 44.Rd3 Rc8 45.Kc3 Re8 46.Kb4 Ba8 47.Ka3 Be4 48.Rd7 Bg2 49.Re7 Rc8 50.Re2 Bb7 51.Rd2 Bd5 52.Rxd5 Rc3+ 53.Kb4 Rc4+ 54.Ka5 Rc5+ 55.Ka6 Ra5+ 56.Kb7
 104/112	3:09:57	183 995 790k	16 144k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc4 Bd5 29.Kb2 Re2+ 30.Kb1 Re1+ 31.Kc2 Re2+ 32.Kd1 Re8 33.Rc5 Bc6 34.Kd2 Bd5 35.Rc7 Bg2 36.Rd7 Bf3 37.Rd3 Bg2 38.Kc1 Ba8 39.Kb2 Bb7 40.Ka3 Be4 41.Rd7 Bg2 42.Re7 Rc8 43.Re2 Bb7 44.Rd2 Bd5 45.Rd3 Re8 46.Rxd5 Re3+ 47.Kb4 Rb3+ 48.Kc4 Rc3+ 49.Kd4 Rd3+ 50.Ke4 Rd4+ 51.Kf3 Rf4+ 52.Ke3 Rf3+ 53.Kd2 Rf2+ 54.Kd3 Rd2+ 55.Ke4 Re2+ 56.Kf3 Rf2+ 57.Kg4
 105/115	3:09:59	184 025 487k	16 144k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc4 Bd5 29.Kb2 Re2+ 30.Kb1 Re1+ 31.Kc2 Re2+ 32.Kd1 Re8 33.Rc5 Bc6 34.Kd2 Bd5 35.Rc7 Bg2 36.Rd7 Bf3 37.Rd3 Bg2 38.Kc1 Ba8 39.Kb2 Bb7 40.Ka3 Be4 41.Rd7 Bg2 42.Re7 Rc8 43.Re2 Bb7 44.Rd2 Bd5 45.Rd3 Re8 46.Rc3 Bc6 47.Rc1 Ra8 48.Kb4 Bf3 49.Rc7 Re8 50.Rc4 Ba8 51.Rc2 Bc6 52.Kc5 Re5+ 53.Kxc6 Rc5+ 54.Kd6 Rd5+ 55.Ke7 Rd7+ 56.Ke8 Rd8+ 57.Ke7
 106/113	3:10:01	184 063 916k	16 144k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc4 Bd5 29.Kb2 Re2+ 30.Kb1 Re1+ 31.Kc2 Re2+ 32.Kd1 Re8 33.Rc5 Bc6 34.Kd2 Bd5 35.Rc7 Bg2 36.Rd7 Bf3 37.Rd3 Bg2 38.Kc1 Ba8 39.Kb2 Bb7 40.Ka3 Be4 41.Rd7 Bg2 42.Re7 Rc8 43.Re2 Bb7 44.Rd2 Bd5 45.Rd3 Re8 46.Rc3 Bc6 47.Rc1 Ra8 48.Kb4 Bf3 49.Rc7 Re8 50.Rc4 Ba8 51.Rc2 Bc6 52.Rd2 Re4+ 53.Kc5 Re5+ 54.Kxc6 Rc5+ 55.Kb7 Rc7+ 56.Kb8 Rc8+ 57.Kb7
 107/121	3:10:03	184 098 601k	16 144k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc4 Bd5 29.Kb2 Re2+ 30.Kb1 Re1+ 31.Kc2 Re2+ 32.Kd1 Re8 33.Rc5 Bc6 34.Kd2 Rd8+ 35.Kc1 Bb7 36.Ra5 Re8 37.Ra3 Ba8 38.Rc3 Bd5 39.Kd2 Bc6 40.Rd3 Rc8 41.Kc3 Re8 42.Kb4 Ba8 43.Ka3 Be4 44.Rd7 Bg2 45.Re7 Rc8 46.Re2 Bb7 47.Rd2 Bd5 48.Rd3 Re8 49.Rc3 Bc6 50.Kb3 Bd5+ 51.Ka4 Ba8 52.Rc7 Be4 53.Re7 Rd8 54.Kb4 Bb7 55.Rxb7 Rd4+ 56.Kc5 Rc4+ 57.Kd5 Rc5+ 58.Kd6 Rc6+ 59.Kd5
 108/119	3:10:09	184 192 550k	16 143k	+11,19	1.b4 Rc8 2.Ra6 Bb5 3.Ra5 Bc6 4.b5 Re8 5.b6 Re2+ 6.Kc3 Re8 7.Rc5 Re3+ 8.Kd2 Re8 9.Rc3 Rd8+ 10.Kc2 Bd5 11.Kb2 Bc6 12.Re3 Bb7 13.Re5 Rc8 14.Ka3 Rd8 15.Kb4 Rd4+ 16.Kc3 Re4 17.Re7 Bd5 18.Rd7 Rc4+ 19.Kd3 Rc8 20.Re7 Rd8 21.Kd4 Bg2+ 22.Kc5 Rd5+ 23.Kc4 Rd8 24.Kc3 Rc8+ 25.Rc7 Re8 26.Kb2 Bd5 27.Ka3 Bb7 28.Rc4 Bd5 29.Kb2 Re2+ 30.Kb1 Re1+ 31.Kc2 Re2+ 32.Kd1 Re8 33.Rc5 Bc6 34.Rc3 Bb7 35.Kc2 Bd5 36.Kb2 Re2+ 37.Kc1 Re8 38.Kd2 Bc6 39.Rd3 Rc8 40.Kc3 Re8 41.Kb4 Ba8 42.Ka3 Be4 43.Rd7 Bg2 44.Re7 Rc8 45.Re2 Bb7 46.Rd2 Bd5 47.Rd3 Re8 48.Rc3 Bc6 49.Kb3 Rd8 50.Kc4 Rd5 51.Ra3 Rd8 52.Re3 Bb7 53.Kb3 Rc8 54.Re7 Rd8 55.Rxb7 Rd3+ 56.Kb4 Rd4+ 57.Kb5 Rd5+ 58.Kc4 Rd4+ 59.Kc5 Rc4+ 60.Kd5
 109/120+	9:57:28	567 457 740k	15 829k	+11,26	1.a8B
I'll let it run 12 more hours ...
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User avatar
Nordlandia
Posts: 2821
Joined: Fri Sep 25, 2015 9:38 pm
Location: Sortland, Norway

Re: A hard endgame (?) study

Post by Nordlandia »

Code: Select all

1r2b1k1/5pPp/3R1P1P/3B4/8/1P6/1K6/8 b - - 0 1

i7-5960X 4.1GHz | 4096 Mb hash | 6-men on Samsung 960 EVO | Analysis by Stockfish 180817 64 BMI2:

3...Ba4 4.b4 Rc8 5.Re6 Rd8 6.Ra6 Be8 7.Bb3 Bb5 8.Re6 Rd2+ 9.Ka3 Rd8 10.Re7 Bc4 11.Ba4 Rb8 12.Be8 Rb6 13.Rc7 Ra6+ 14.Kb2 Ra2+ 15.Kb1 Ra8 16.Bxf7+ Bxf7 17.b5 Bg6+ 18.Kb2 Be8 19.b6 Bd7 20.b7 Rb8 21.Kc3 Re8 22.Kd4 Rd8 23.Kc4 Re8 24.Kd5 Rd8 25.Kd6 Kf7 26.Rxd7+ Rxd7+ 27.Kxd7 Kxf6 
  +- (132.59)  Depth: 48/50   00:00:10  284MN, tb=3127228
(18.08.2017)
[pgn][Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "New game"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "4b1k1/P4pPp/1R3P1P/2r5/8/1P6/1K6/8 w - - 0 1"]
[PlyCount "54"]

{[#]} 1. a8=B Rb5 2. Rd6 Rb8 3. Bd5 Ba4 4. b4 Rc8 5. Re6 Rd8 6. Ra6 Be8 7. Bb3
Bb5 8. Re6 Rd2+ 9. Ka3 Rd8 10. Re7 Bc4 11. Ba4 Rb8 12. Be8 Rb6 13. Rc7 Ra6+ 14.
Kb2 Ra2+ 15. Kb1 Ra8 16. Bxf7+ Bxf7 17. b5 Bg6+ 18. Kb2 Be8 19. b6 Bd7 20. b7
Rb8 21. Kc3 Re8 22. Kd4 Rd8 23. Kc4 Re8 24. Kd5 Rd8 25. Kd6 Kf7 26. Rxd7+ Rxd7+
27. Kxd7 Kxf6 *

[/pgn]
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Vinvin
Posts: 5228
Joined: Thu Mar 09, 2006 9:40 am
Full name: Vincent Lejeune

Re: A hard endgame (?) study

Post by Vinvin »

Vinvin wrote:
Nordlandia wrote:Sokolsky - Ravinsky, USSR 1938 (or 1933)

a8=B is supposed to win, however no engine see a breakthrough.

[d]4b1k1/P4pPp/1R3P1P/2r5/8/1P6/1K6/8 w - - 0 0

https://timkr.home.xs4all.nl/chess2/minor.htm
Finally found by SF after 9h57m ! (see last line)
CPU 6*4GHz, 8 GB hash

Code: Select all

Stockfish_170810_x64_modern:
......
 109/120+	9:57:28	567 457 740k	15 829k	+11,26	1.a8B
I'll let it run 12 more hours ...
No new line after 13.5 hours :(
Screen capture : https://www.dropbox.com/s/n35qkhp1pr2le ... 8.png?dl=0
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Paloma
Posts: 1167
Joined: Thu Dec 25, 2008 9:07 pm
Full name: Herbert L

Re: A hard endgame (?) study

Post by Paloma »

It's a mate in 34 or 33

[pgn][Event "?"]
[Site "?"]
[Date "2017.08.18"]
[Round "?"]
[White "A hard endgame (?) study"]
[Black "?"]
[Result "1-0"]
[Annotator "HL"]
[SetUp "1"]
[FEN "4b1k1/P4pPp/1R3P1P/2r5/8/1P6/1K6/8 w - - 0 1"]
[PlyCount "29"]
1. a8=B $3 {33#} (1. a8=Q $2
Rc2+ 2. Ka1 Rc1+ {and the checks can never be stopped.}) (1. Rb8 $2 Rc2+ 2. Ka3
Ra2+ 3. Kb4 Ra4+ 4. Kc5 Ra5+ 5. Kd6 Ra6+ 6. Ke7 Rxa7+ 7. Kd8 Rd7+ 8. Kc8 Rc7+ {
and the checks can never be stopped.}) (1. Rb4 $2 Rc8 2. Rb7 Ra8 $4 3. Rb8 Rxb8
4. axb8=N) (1. a8=N Rc8 2. Ra6 (2. Nc7 Rxc7 3. Rb8 Rc2+ {draw}) 2... Rxa8 3.
Rxa8 {stalemate}) 1... Rc8 {Sokolsky - Ravinsky, USSR 1938 (or 1933)} (1... Re5
2. Bf3 $1 (2. Rd6 $2 Rb5 $1 (2... Bc6 $2 3. Rd8+ Re8 (3... Be8 $2 4. Bd5 Re3 5.
Ka2 {19#}) 4. Rxe8+ Bxe8 5. Be4 $18) 3. Kc3 Rb8 4. Be4 Bb5 5. b4 $18) 2... Rf5
3. Be4 Rc5 (3... Re5 4. Bd3 {22#} Re3 5. Bc4) 4. Rb7 {23#} Rh5 5. Re7 Bc6 6.
Bd3 Rxh6 7. Rxf7 Kxf7 8. Bc4+) 2. Be4 $5 ({or} 2. Bd5 $3 Rd8 {28#} (2... Bc6 3.
Bxc6 Ra8 4. Ba4 Re8 5. Ka3 Ra8 6. Re6 fxe6 7. Kb2 Rd8 8. b4 Rd4 9. Ka3 Rf4 10.
b5 Rf3+ 11. Bb3 Rxf6) 3. Bc4 Bb5 4. Bxf7+ Kxf7 5. Rxb5 Kxf6 6. Rc5
Rg8 7. Rc6+ Kg5 8. Kc3 $18) 2... Bc6 (2... Bd7 3. Bd5 Rc7 4. Rb8+ Bc8 5. Bxf7+
Kxf7 6. b4 Rc4 7. b5 Rb4+ 8. Kc3 $18) (2... Rd8 {<Weiß setzt Matt: +- (#33)
Tiefe: 58/91 01:39:27 86649MN} 3. Bf5 {33#} Rd2+ 4. Kc3 Rd8 5. Kb4 Rd4+ 6. Kc5
Rd8 7. Rb7 Bd7 8. Bd3 Be6 9. b4 Rc8+ 10. Kd4 Rd8+ 11. Ke5 Bc4 12. Bf5 Rd5+ 13.
Kf4 Rd4+ 14. Ke3 Rd8 15. Rc7 Bb5 16. Kf4 Be8 17. Re7 Rd4+ 18. Ke3 (18. Ke5 $1)
18... Rd8 19. Bg4 Bb5 20. Bh5 Bc4 21. b5 Rd3+ 22. Ke4 Rd8 23. b6 Bd3+ 24. Kf4
Bc4 25. Rc7 (25. b7 $1) 25... Rd4+ 26. Ke5 Rd5+ 27. Ke4 Rd8 28. b7 Bd5+ 29. Kf4
Be6 30. Bxf7+ Bxf7 31. Rc8 Be8 32. Rxd8 Kf7 33. b8=Q Ba4 34. g8=Q+ Kxf6 35.
Qe5#) 3. Bxc6 $1 {27#; Now Black must threaten his stalemate-perpetual.} Ra8 (
3... Rd8 4. Bd5 {[%cal Rd5f7] 6#}) (3... Re8 4. Be4 {[%cal Re4h7]} Rc8 5. Bxh7+
) 4. Ba4 $1 {26# Houd501 (after some backwards/vorwards) 3...Ra8 4.Ba4
Re8 5.Ka3 Ra8 6.Re6 fxe6 7.Kb2 Rd8 8.b4 Rd4 9.Ka3 Rf4 10.b5 Rf3+ 11.Bb3 Rxf6
12.b6 Rxh6 13.b7 Kxg7 14.b8Q Kf6 15.Qd8+ Kg6 16.Qg8+ Kf6 17.Qxe6+ Kg5 18.Qe5+
Kg6 19.Qf4 Rh1 20.Qe4+ Kg5 21.Qxh1 Kf4 22.Qxh7 Ke5 23.Qh5+ Ke4 24.Bd5+ Kf4 25.
Kb2 Ke3 26.Qg4 Kd2 27.Qf3 Ke1 28.Bc4 Kd2 29.Qe2# Weiß setzt Matt: +- (#26)
Tiefe: 65/87 00:25:40 24138MN} Re8 (4... Rc8 5. Re6 $1 {13#})
5. Ka3 $1 {and Black must give up the e-line, enabling Re6 after all} Ra8 6.
Re6 $1 fxe6 $1 (6... Rd8 7. Ra6 $1 {6#}) (6... Rxa4+ 7. bxa4 {9#}) 7. Kb4 (7.
Kb2 Rd8 8. b4 Rd4 9. Ka3 Rf4 10. b5 Rf3+ 11. Bb3 Rxf6 12. b6 Rxh6 13. b7 Kxg7
14. b8=Q {16#} Rh5 (14... Kf6 15. Qd8+ {14#}) (14... Rf6 15. Qe5 {15#} Kg6 16.
Bc2+)) 7... Kf7 {the Rook had to guard the eighth rank against 8.Be8} (7... Rd8
8. Kc4 {25#} Rc8+ 9. Kd4) 8. Bc6 {22#} Rb8+ 9. Kc5 {and Black is helpless
against the threat of 10.Be4 followed by Bxh7} Rc8 (9... Kg8 10. Be4 Rxb3 11.
Bxh7+ Kxh7 $19) (9... Rxb3 10. Be8+ {13#} Kxf6 11. g8=Q) 10. Kd6 Kxf6 11. Be4
Kg5 12. Kd7 Rb8 13. Bxh7 Kxh6 14. g8=Q Rxg8 15. Bxg8 {15#} 1-0
[/pgn]
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peter
Posts: 3185
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: A hard endgame (?) study

Post by peter »

Hi Herbert!
Paloma wrote: It's a mate in 34 or 33
Or 29?
After 1.a8B Rc8:

B1r1b1k1/5pPp/1R3P1P/8/8/1P6/1K6/8 w - - 0 1

Analysis by Stockfish 060917 64 POPCNT:

2.Bd5 Bc6 3.Bxc6 Ra8 4.Ba4 Re8 5.Ka3 Ra8 6.Re6 fxe6 7.Kb4 Rd8 8.Kc3 Rc8+ 9.Kd4 Kf7 10.b4 Kxf6 11.Bc2 Rxc2 12.g8Q e5+ 13.Kd3 Rh2 14.Qg7+ Ke6 15.Qxh7 Rh3+ 16.Kc4 Rh4+ 17.Kc5 Kf6 18.Qg7+ Kf5 19.h7 e4 20.h8Q Rxh8 21.Qxh8 e3 22.Kd5 Kg4 23.Ke5 Kf3 24.Qh5+ Kf2 25.Ke4 e2 26.Qf3+ Kg1 27.Qxe2 Kh1 28.Kf3 Kg1 29.Qg2#
+- (#28) Depth: 67/62 00:01:06 2450MN

Your found 2.Bd5 (commented with !! and "or" could be called a Major Dual anyhow yet too, which is a pity for the study as for tournament- judging) is at least as well as authors' solution 2.Be4, if it's the original one indeed.

Edit: didn't see the link, Jon gave with the Position till now:

https://timkr.home.xs4all.nl/chess2/minor.htm

Have to look at the other first moves of Black closer anyhow, e.g. 1...Rb5 seems to hold some longer
Peter.
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peter
Posts: 3185
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: A hard endgame (?) study

Post by peter »

peter wrote:
1...Rb5 seems to hold some longer
Not yet.

B3b1k1/5pPp/1R3P1P/1r6/8/1P6/1K6/8 w - - 0 1

Analysis by Stockfish 060917 64 POPCNT:

2.Rxb5 Bxb5 3.Be4 Bd3 4.Bxh7+ Kxh7 5.Kc3 Ba6 6.Kd4 Bb5 7.Kc5 Be2 8.b4 Bf3 9.b5 Ba8 10.Kd6 Kg8 11.Kc7 Bf3 12.b6 Be4 13.b7 Bxb7 14.Kxb7 Kh7 15.Kc6 Kg8 16.Kc7 Kh7 17.Kd6 Kg6 18.g8Q+ Kf5 19.h7 Ke4 20.h8Q Kd4 21.Qg3 Kc4 22.Qb8 Kd4 23.Qb4#
+- (#22) Depth: 98/44 00:05:08 14558MN

And after the last 2 plies backward to the starting position SF has the #29 in hash soon again:

4b1k1/P4pPp/1R3P1P/2r5/8/1P6/1K6/8 w - - 0 1

Analysis by Stockfish 060917 64 POPCNT:

1.a8B Rc8 2.Bd5 Bc6 3.Bxc6 Ra8 4.Ba4 Re8 5.Ka3 Ra8 6.Re6 fxe6 7.Kb2 Rd8 8.Kc3 Rc8+ 9.Kd4 Kf7 10.b4 Kxf6 11.Bc2 Rxc2 12.g8Q e5+ 13.Ke3 Rc3+ 14.Ke4 Rc2 15.Qxh7 Rc4+ 16.Ke3 Rc3+ 17.Kf2 Rc1 18.Qg7+ Ke6 19.h7 Rh1 20.h8Q Rxh8 21.Qxh8 Kd7 22.Qxe5 Kc6 23.Qe6+ Kb7 24.Qd6 Ka7 25.Qc6 Kb8 26.Qd7 Ka8 27.b5 Kb8 28.b6 Ka8 29.Qa7#
+- (#29) Depth: 72/58 00:03:00 6803MN
Peter.
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Eelco de Groot
Posts: 4561
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Re: A hard endgame (?) study

Post by Eelco de Groot »

I have 2...Bd7 at the moment as one better than Bc6. But probably wrong. 2...Rd8 would be #25 and 2...Rb5 should be shorter than #20 but I suspect it could be just missing from the best moves. Which should not happen of course.

I don't quite get why Herbert would say it is Mate in 33 or 34, did he mean after Be4. Because he already gives much better estimates after 2. Bd5


[D]2r1b1k1/5pPp/1R3P1P/8/4B3/1P6/1K6/8 b - -

Engine: Test Imbalance HT (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott

65 189:56 +M29 2...Bd7 3.Bd5 Bc6 4.Bxc6 Ra8 5.Ba4 Re8
6.Ka3 Ra8 7.Re6 fxe6 8.b4 Kf7 9.Kb3 Rc8
10.Bb5 Rd8 11.Bc6 Rd3+ 12.Kc2 Rg3
13.Be4 Kxf6 14.Bxh7 Rg2+ 15.Kb3 Rg3+ (219.616.929.432) 19270

65 189:56 +M28 2...Bc6 3.Bxc6 Ra8 4.Ba4 Re8 5.Ka3 Ra8
6.Re6 fxe6 7.b4 Kf7 8.Kb3 Rc8 9.Bb5 Rd8
10.Bc6 Rd3+ 11.Kc2 Rg3 12.Be4 Kxf6
13.Bxh7 Rg2+ 14.Kb3 Rg3+ 15.Kc4 Rg4+ (219.616.929.432) 19270

64 189:56 +M25 2...Rd8 3.b4 Rd2+ 4.Kc3 Rd8 5.Rb7 Rc8+
6.Kb2 Rd8 7.Bc2 Bc6 8.Bxh7+ Kxh7
9.Rxf7 Rd2+ 10.Kc3 Rh2 11.Rd7 Rxh6
12.Rd8 Bd5 13.Rh8+ Kg6 14.Kd4 Bf7
15.Rxh6+ Kxh6 (219.616.929.432) 19270

64 189:56 +M20 2...Bb5 3.Rb7 Ba6 4.Bxh7+ Kxh7
5.Rxf7 Rg8 6.Rf8 Bb7 7.b4 Bd5 8.b5 Kxh6
9.Rxg8 Bxg8 10.b6 Be6 11.b7 Kg5
12.b8Q Kxf6 13.g8Q Bxg8 14.Qxg8 Ke7
15.Kc3 Kf6 (219.616.929.432) 19270

64 189:56 +M20 2...Ba4 3.Rb7 Bxb3 4.Bxh7+ Kxh7
5.Kxb3 Kxh6 6.Rxf7 Rb8+ 7.Kc4 Rc8+
8.Kb5 Rb8+ 9.Kc6 Rc8+ 10.Kd7 Ra8
11.Rf8 Ra7+ 12.Kd6 Ra6+ 13.Kc5 Ra5+
14.Kb6 Rg5 15.g8Q Rg6 (219.616.929.432) 19270
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
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peter
Posts: 3185
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: A hard endgame (?) study

Post by peter »

Eelco de Groot wrote:I have 2...Bd7 at the moment as one better than Bc6. But probably wrong. 2...Rd8 would be #25 and 2...Rb5 should be shorter than #20 but I suspect it could be just missing from the best moves.
After 1.a8B Rc8 2.Bd5 Bd7:

2r3k1/3b1pPp/1R3P1P/3B4/8/1P6/1K6/8 w - - 0 1

Analysis by Stockfish 060917 64 POPCNT:

3.Rb7 Re8 4.Bc4 Rd8 5.b4 Be8 6.b5 Rd2+ 7.Kc3 Rd8 8.b6 Ra8 9.Re7 Ra3+ 10.Kd4 Ra8 11.b7 Rb8 12.Bd5 Rd8 13.Kc5 Rb8 14.Kb6 Rd8 15.Ka7 Ra8+ 16.bxa8B Bd7 17.Bxf7#
+- (#15) Depth: 80/30 00:00:42 1467MN

After 2...Rd8:

3rb1k1/5pPp/1R3P1P/3B4/8/1P6/1K6/8 w - - 0 1

Analysis by Stockfish 060917 64 POPCNT:

3.Bc4 Ba4 4.b4 Re8 5.Rb7 Bb3 6.Rxf7 Bxc4 7.Rc7 Bd5 8.Kc3 Ra8 9.b5 Ra3+ 10.Kd4 Ra4+ 11.Kc5 Rc4+ 12.Kd6 Rxc7 13.Kxc7 Kf7 14.g8Q+ Kxg8 15.Kd6 Kf7 16.Kxd5 Kxf6 17.b6 Kg5 18.b7 Kxh6 19.b8Q Kg5 20.Qe5+ Kg6 21.Ke6 h6 22.Qf5+ Kg7 23.Qf7+ Kh8 24.Kf6 h5 25.Qg7#
+- (#23) Depth: 57/46 00:00:35 1228MN

And after 2...Bc6:

2r3k1/5pPp/1Rb2P1P/3B4/8/1P6/1K6/8 w - - 0 1

Analysis by Stockfish 060917 64 POPCNT:

3.Bxc6 Ra8 4.Ba4 Re8 5.Ka3 Ra8 6.Re6 fxe6 7.Kb2 Rd8 8.Kc3 Rc8+ 9.Kd4 Kf7 10.b4 Kxf6 11.Bc2 Rxc2 12.g8Q e5+ 13.Ke3 Rc3+ 14.Ke4 Rc2 15.Qxh7 Rc4+ 16.Kf3 Rc3+ 17.Kg4 Rc4+ 18.Kh5 Rf4 19.Qh8+ Kf7 20.Qxe5 Rf1 21.Qc5 Rh1+ 22.Kg5 Ke6 23.Qc6+ Ke5 24.Qxh1 Kd4 25.h7 Ke3 26.h8Q Kd3 27.Qf3+ Kc2 28.Qfc3+ Kb1 29.Qb2#
+- (#27) Depth: 70/54 00:00:02 64078kN

Only one move longer than 2.Bd5 2.Be4 seems to be:

2r1b1k1/5pPp/1R3P1P/8/4B3/1P6/1K6/8 b - - 0 1

Analysis by Stockfish 060917 64 POPCNT:

2...Bd7 3.Bd5 Bc6 4.Bxc6 Ra8 5.Ba4 Re8 6.Ka3 Ra8 7.Re6 fxe6 8.Kb2 Rd8 9.Kc3 Rc8+ 10.Kd4 Kf7 11.b4 Kxf6 12.Bc2 Rxc2 13.g8Q e5+ 14.Ke3 Rc3+ 15.Ke4 Rc2 16.Qxh7 Rc4+ 17.Kf3 Rc3+ 18.Kg4 Rc4+ 19.Kh5 Rf4 20.Qh8+ Kf7 21.Qxe5 Rf1 22.Qc5 Rh1+ 23.Kg5 Ke6 24.Qc6+ Ke5 25.Qxh1 Kd4 26.h7 Ke3 27.h8Q Kd3 28.Qf3+ Kc2 29.Qfc3+ Kb1 30.Qb2#
+- (#28) Depth: 64/57 00:00:22 851MN

That's not to problem as for the judgement of the study cause it isn't a # in x- puzzle.
The "problem" is the Major Dual in the second move
Peter.
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Eelco de Groot
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Re: A hard endgame (?) study

Post by Eelco de Groot »

Hi peter,

I think i see what is wrong, I accidently was analyzing the position after 2. Be4

[D]2r1b1k1/5pPp/1R3P1P/8/4B3/1P6/1K6/8 b - -

and there indeed Bd7 seems to be best... Sorry for the confusion.

At 70 ply


2r1b1k1/5pPp/1R3P1P/8/4B3/1P6/1K6/8 b - -

Engine: Test Imbalance HT (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G.

70 273:59 +M29 2...Bd7 3.Bd5 Bc6 4.Bxc6 Ra8 5.Ba4 Re8
6.Ka3 Ra8 7.Re6 fxe6 8.b4 Kf7 9.Kb3 Rc8
10.Bb5 Rd8 11.Bc6 Rd3+ 12.Kc2 Rg3
13.Be4 Kxf6 14.Bxh7 Rg2+ 15.Kb3 Rg3+ (317.025.562.829) 19284

70 273:59 +M28 2...Bc6 3.Bxc6 Ra8 4.Ba4 Re8 5.Ka3 Ra8
6.Re6 fxe6 7.b4 Kf7 8.Kb3 Rc8 9.Bb5 Rd8
10.Bc6 Rd3+ 11.Kc2 Rg3 12.Be4 Kxf6
13.Bxh7 Rg2+ 14.Kb3 Rg3+ 15.Kc4 Rg4+ (317.025.562.829) 19284

70 273:59 +M25 2...Rd8 3.b4 Rd2+ 4.Kc3 Rd8 5.Rb7 Rc8+
6.Kb2 Rd8 7.Bc2 Bc6 8.Bxh7+ Kxh7
9.Rxf7 Rd2+ 10.Kc3 Rh2 11.Rd7 Rxh6
12.Rd8 Bd5 13.Rh8+ Kg6 14.Kd4 Bf7
15.Rxh6+ Kxh6 (317.025.562.829) 19284

70 273:59 +M20 2...Bb5 3.Rb7 Ba6 4.Bxh7+ Kxh7
5.Rxf7 Rg8 6.Rf8 Bb7 7.b4 Bd5 8.b5 Kxh6
9.Rxg8 Bxg8 10.b6 Kg6 11.b7 Kxf6
12.b8Q Kxg7 13.Kc3 Bf7 14.Kd4 Kf6
15.Qe5+ Kg6 (317.025.562.829) 19284

69 273:59 +M20 2...Ba4 3.Rb7 Bxb3 4.Bxh7+ Kxh7
5.Kxb3 Kxh6 6.Rxf7 Rb8+ 7.Kc4 Rc8+
8.Kb5 Rb8+ 9.Kc6 Rc8+ 10.Kd7 Ra8
11.Rf8 Ra7+ 12.Kd6 Ra6+ 13.Kc5 Ra5+
14.Kb6 Rg5 15.g8Q Rg6 (317.025.562.829) 19284

After 2. Bd5 then some Blitz analysis:


[D]2r1b1k1/5pPp/1R3P1P/3B4/8/1P6/1K6/8 b - -

Engine: Test Imbalance HT (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G.

48 6:24 +M30 2...Rd8 3.Be4 Bb5 4.Bxh7+ Kxh7
5.Rxb5 Kxh6 6.Rd5 Rg8 7.Rc5 Kg6
8.Rc6 Kf5 9.Kc3 Rd8 10.Kc4 Re8 11.b4 Re4+
12.Kc3 Re3+ 13.Kb2 Re2+ 14.Rc2 Re8
15.Rf2+ Kg6 (7.437.151.574) 19356

48 6:24 +M26 2...Bc6 3.Bxc6 Ra8 4.Ba4 Re8 5.Ka3 Ra8
6.Re6 fxe6 7.b4 Kf7 8.Kb3 Rc8 9.Bb5 Rd8
10.Bc6 Rd3+ 11.Kc2 Rg3 12.Be4 Kxf6
13.Bxh7 Rg2+ 14.Kd3 Rg3+ 15.Ke4 Rg4+ (7.437.151.574) 19356

48 6:24 +M20 2...Ba4 3.Bxf7+ Kxf7 4.bxa4 Re8 5.a5 Re2+
6.Kc3 Re3+ 7.Kd2 Re8 8.Rb7+ Kxf6
9.a6 Rd8+ 10.Kc3 Rc8+ 11.Kb2 Rg8
12.a7 Rd8 13.Rb8 Rd2+ 14.Kc3 Rh2
15.a8Q Rh3+ (7.437.151.574) 19356

48 6:24 +M17 2...Rc7 3.Bxf7+ Rxf7 4.Rb8 Rf8
5.gxf8Q+ Kxf8 6.b4 Kf7 7.Rxe8 Kxe8
8.b5 Kd7 9.b6 Ke6 10.b7 Kxf6 11.b8Q Ke6
12.Qg8+ Kf6 13.Qxh7 Kg5 14.Qg8+ Kxh6
15.Kc3 Kh5 (7.437.151.574) 19356

48 6:24 +M17 2...Bd7 3.Rb7 Ra8 4.Kc3 Rc8+ 5.Kd4 Rd8
6.Ke5 Re8+ 7.Kd6 Be6 8.Re7 Rd8+
9.Kc7 Rc8+ 10.Kb7 Bxd5+ 11.Kxc8 Be6+
12.Kd8 Bd7 13.b4 Bc6 14.b5 Bd7 15.b6 Bb5 (7.437.151.574) 19356
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
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