Featured Item for testing.

[zullil]

And you used to analyze this position.

I obtained the analysis by running Stockfish directly from a command line.

I did the same with Komodo-9.2. It finds mate, but not a minimal mate:

Code: Select all

info depth 35 time 5322490 nodes 217306819155 score mate 29 nps 40828029 hashfull 315 tbhits 0 pv c3c4 g7d7 b5b4 d7g7 b4b3 b2b1 d4f3 b1b2 f3d2 b2a3 c4c2 g7h7 h3g2 h7b7 g2f3 b7b8 b3b2 b8b2 d2c4 a3b3 c2b2 b3c4 b2b6 c4d5 f3f4 d5c5 b6e6 c5d5 e6f6 d5c4 f4e4 c4c5 f6e6 c5b4 e6c6 b4b5 e4d5 b5b4 c6c5

[Vinvin]

I will present a very interesting position to test engines. I ask to write or some of chess engines in position below he found the mat.



Black start and place mat.

Try Stockfish-Matefinder without EGTB :
FEN: 8/6R1/8/1p6/3n4/2r4k/1K6/8 b - - 0 1

Code: Select all

Stockfish 6 MF x64 sse:
...
 36/43	00:01	 14.133k	13.184k	-3,85	1. ... Rc2+ 2.Ka1 Kh4 3.Rd7 Rc4 4.Rg7 b4 5.Ka2 Rc2+ 6.Ka1 b3 7.Rb7 Rc4 8.Kb2 Kg4 9.Rb6 Kf3 10.Rb8 Kf4 11.Rb7 Ke3 12.Rb8 Rc2+ 13.Kb1 Kd2 14.Rd8 Kd3 15.Rd7 Rc6 16.Rh7 Rc4 17.Rh4 Nf3 18.Rh3 Ke4 19.Kb2 Nd2 20.Rh4+ Kd3 21.Rh3+ Kd4 22.Ka3
 37/43	00:01	 16.246k	13.527k	-3,85	1. ... Rc2+ 2.Ka1 Kh4 3.Rd7 Rc4 4.Rg7 b4 5.Ka2 Rc2+ 6.Ka1 b3 7.Rb7 Rc4 8.Kb2 Kg4 9.Rb6 Kf3 10.Rb8 Kf4 11.Rb7 Ke3 12.Rb8 Rc2+ 13.Kb1 Kd2 14.Rd8 Kd3 15.Rd7 Rc6 16.Rh7 Rc4 17.Rh4 Nf3 18.Rh3 Ke4 19.Kb2 Nd2 20.Rh4+ Kd3 21.Rh3+ Kd4 22.Ka3
 38/51	00:01	 18.220k	13.699k	-3,85	1. ... Rc2+ 2.Ka1 Kh4 3.Rd7 Rc4 4.Rg7 b4 5.Ka2 Rc2+ 6.Ka1 b3 7.Rb7 Rc4 8.Kb2 Kg4 9.Rb6 Kf3 10.Rb8 Kf4 11.Rb7 Ke3 12.Rb8 Rc2+ 13.Kb1 Kd2 14.Rd8 Kd3 15.Rd7 Rc6 16.Kb2 Rc4 17.Rd8 Ke2 18.Re8+ Kd2 19.Rd8 Kd3 20.Kb1 Ke4 21.Rg8 Kf4 22.Rh8 Rc2
 39/63-	00:03	 44.661k	14.677k	-10,89	1. ... Rc2+
 39/63-	00:03	 53.424k	14.701k	-14,43	1. ... Rc2+
 39/63-	00:04	 69.177k	14.527k	-39,62	1. ... Rc2+
 39/63	00:05	 76.077k	14.605k	-44,26	1. ... Rc2+ 2.Ka3 Rc4 3.Re7 b4+ 4.Ka2 b3+ 5.Ka3 Kg2 6.Re1 Kf2 7.Rh1 Rc2 8.Kb4 Ke2 9.Rh2+ Ke1 10.Rh1+ Kf2 11.Rd1 Ke2 12.Rh1 b2 13.Ka3 Nf3 14.Rb1 Nd2 15.Rxb2 Nc4+ 16.Kb3 Rxb2+ 17.Kxc4 Ra2 18.Kb5 Kd3 19.Kc5 Ke4 20.Kd6 Rd2+ 21.Ke6 Rd5 22.Kf6 Rd6+ 23.Ke7 Ke5 24.Ke8 Kd5 25.Ke7
 40/63-	00:05	 78.109k	14.624k	-44,32	1. ... Rc2+
 40/63	00:05	 80.614k	14.612k	-44,34	1. ... Rc2+ 2.Ka3 Rc4 3.Re7 b4+ 4.Ka2 b3+ 5.Ka3 Kg2 6.Re1 Kf2 7.Rh1 Rc2 8.Kb4 Ke2 9.Rh2+ Ke1 10.Rh1+ Kf2 11.Rd1 Ke2 12.Rh1 b2 13.Ka3 Nf3 14.Rb1 Nd2 15.Rxb2 Nc4+ 16.Kb3 Rxb2+ 17.Kxc4 Rd2 18.Kc5 Ke3 19.Kc6 Ke4 20.Kc5 Rg2 21.Kc6 Rg6+ 22.Kc7 Kd5 23.Kd7 Rg7+ 24.Ke8 Ke6 25.Kd8 Kd6
 41/63-	00:05	 82.605k	14.618k	-44,40	1. ... Rc2+
 41/63-	00:05	 84.366k	14.591k	-44,46	1. ... Rc2+
 41/63-	00:06	 98.133k	14.427k	-46,39	1. ... Rc2+
 41/63	00:07	 112.379k	14.740k	-47,43	1. ... Rc2+ 2.Ka3 Rc4 3.Ka2 b4 4.Kb2 b3 5.Kb1 Nf3 6.Rd7 Kg3 7.Kb2 Nd4 8.Re7 Rc2+ 9.Kb1 Kf2 10.Rb7 Rc4 11.Ka1 Ke2 12.Kb2 Kd2 13.Rb8 Rc2+ 14.Ka3 Kd3 15.Rb7 Ra2+ 16.Kb4 b2 17.Kc5 Ra5+ 18.Kd6 Nb5+ 19.Ke6 b1Q 20.Re7 Qe1+ 21.Kf6 Qxe7+ 22.Kxe7 Ra6 23.Kf8 Kd4 24.Ke7 Nc3 25.Ke8
 42/63	00:08	 118.553k	14.778k	-47,39	1. ... Rc2+ 2.Ka3 Rc4 3.Ka2 b4 4.Kb2 b3 5.Rg1 Rc2+ 6.Ka3 Kh2 7.Rf1 Rc4 8.Rf2+ Kg3 9.Rf1 Kg2 10.Rb1 Kf2 11.Rh1 Rc2 12.Kb4 Ke2 13.Rh2+ Ke1 14.Rh1+ Kf2 15.Rd1 Ke2 16.Rb1 Kd3 17.Rd1+ Rd2 18.Rh1 b2 19.Kc5 Kc2 20.Kd5 b1Q 21.Rxb1 Kxb1 22.Ke5 Kb2 23.Kf6 Kc3 24.Kf7 Kd3 25.Kf6 Ke4
 43/63-	00:08	 119.526k	14.755k	-47,45	1. ... Rc2+
 43/63	00:08	 123.144k	14.808k	-47,50	1. ... Rc2+ 2.Ka3 Rc4 3.Ka2 b4 4.Kb2 b3 5.Rg1 Rc2+ 6.Ka3 Kh2 7.Rf1 Rc4 8.Rf2+ Kg3 9.Rf1 Kg2 10.Rb1 Kf2 11.Rh1 Rc2 12.Kb4 Ke2 13.Rh2+ Ke1 14.Rh1+ Kf2 15.Rd1 Ke2 16.Rb1 Kd3 17.Rd1+ Rd2 18.Rh1 b2 19.Kc5 Kc2 20.Kd5 b1Q 21.Rxb1 Kxb1 22.Ke5 Kb2 23.Kf6 Kc3 24.Kf7 Kd3 25.Kf6 Ke4
 44/63	00:08	 127.309k	14.909k	-47,50	1. ... Rc2+ 2.Ka3 Rc4 3.Ka2 b4 4.Kb2 b3 5.Rg1 Rc2+ 6.Ka3 Kh2 7.Rf1 Rc4 8.Rf2+ Kg3 9.Rf1 Kg2 10.Rb1 Kf2 11.Rh1 Rc2 12.Kb4 Ke2 13.Rh2+ Ke1 14.Rh1+ Kf2 15.Rd1 Ke2 16.Rb1 Kd3 17.Rd1+ Rd2 18.Rh1 b2 19.Kc5 Kc2 20.Kd5 b1Q 21.Rxb1 Kxb1 22.Ke5 Kb2 23.Kf6 Kc2 24.Ke7 Kb3 25.Kf7 Kc3 26.Kf6
 45/63	00:08	 131.387k	15.005k	-47,50	1. ... Rc2+ 2.Ka3 Rc4 3.Ka2 b4 4.Kb2 b3 5.Rg1 Rc2+ 6.Ka3 Kh2 7.Rf1 Rc4 8.Rf2+ Kg3 9.Rf1 Kg2 10.Rb1 Kf2 11.Rh1 Rc2 12.Kb4 Ke2 13.Rh2+ Ke1 14.Rh1+ Kf2 15.Rd1 Ke2 16.Rb1 Kd3 17.Rd1+ Rd2 18.Rh1 b2 19.Kc5 Kc2 20.Kd5 b1Q 21.Rxb1 Kxb1 22.Ke5 Kb2 23.Kf6 Kc2 24.Ke7 Kd3 25.Kf6 Ke4 26.Kf7 Ra2
 46/63	00:08	 134.087k	15.052k	-47,50	1. ... Rc2+ 2.Ka3 Rc4 3.Ka2 b4 4.Kb2 b3 5.Rg1 Rc2+ 6.Ka3 Kh2 7.Rf1 Rc4 8.Rf2+ Kg3 9.Rf1 Kg2 10.Rb1 Kf2 11.Rh1 Rc2 12.Kb4 Ke2 13.Rh2+ Ke1 14.Rh1+ Kf2 15.Rd1 Ke2 16.Rb1 Kd3 17.Rd1+ Rd2 18.Rh1 b2 19.Kc5 Kc2 20.Kd5 b1Q 21.Rxb1 Kxb1 22.Ke5 Kb2 23.Kf6 Kc2 24.Ke7 Kd3 25.Kf6 Ke4 26.Kf7 Ra2 27.Kg6
 47/63	00:09	 143.619k	15.301k	-47,50	1. ... Rc2+ 2.Ka3 Rc4 3.Ka2 b4 4.Kb2 b3 5.Rg1 Rc2+ 6.Ka3 Kh2 7.Rf1 Rc4 8.Rf2+ Kg3 9.Rf1 Kg2 10.Rb1 Kf2 11.Rh1 Rc2 12.Kb4 Ke2 13.Rh2+ Ke1 14.Rh1+ Kf2 15.Rd1 Ke2 16.Rb1 Kd3 17.Rd1+ Rd2 18.Rh1 b2 19.Kc5 Kc2 20.Kd5 b1Q 21.Rxb1 Kxb1 22.Ke5 Kb2 23.Kf6 Kc2 24.Ke7 Kd3 25.Kf6 Ke4 26.Kf7 Ra2 27.Kg6 Rg2+ 28.Kh5
 48/63	00:09	 147.299k	15.315k	-47,50	1. ... Rc2+ 2.Ka3 Rc4 3.Ka2 b4 4.Kb2 b3 5.Rg1 Rc2+ 6.Ka3 Kh2 7.Rf1 Rc4 8.Rf2+ Kg3 9.Rf1 Kg2 10.Rb1 Kf2 11.Rh1 Rc2 12.Kb4 Ke2 13.Rh2+ Ke1 14.Rh1+ Kf2 15.Rd1 Ke2 16.Rb1 Kd3 17.Rd1+ Rd2 18.Rh1 b2 19.Kc5 Kc2 20.Kd5 b1Q 21.Rxb1 Kxb1 22.Ke5 Kb2 23.Kf6 Kc2 24.Kg6 Kd3 25.Kg5 Ke4 26.Kg4 Rb2 27.Kg3 Kf5 28.Kh4
 49/63	00:10	 173.504k	16.049k	-47,50	1. ... Rc2+ 2.Ka3 Rc4 3.Ka2 b4 4.Kb2 b3 5.Rg1 Rc2+ 6.Ka3 Kh2 7.Rf1 Rc4 8.Rf2+ Kg3 9.Rf1 Kg2 10.Rb1 Kf2 11.Rh1 Rc2 12.Kb4 Ke2 13.Rh2+ Ke1 14.Rh1+ Kf2 15.Rd1 Ke2 16.Rb1 Kd3 17.Rd1+ Rd2 18.Rh1 b2 19.Kc5 Kc2 20.Kd5 b1Q 21.Rxb1 Kxb1 22.Ke5 Kb2 23.Kf6 Kc2 24.Kg6 Kd3 25.Kh5 Ke4 26.Kg4 Rb2 27.Kg3 Kf5 28.Kh4 Nb5
 50/67	00:12	 211.886k	16.747k	-47,54	1. ... Rc2+ 2.Ka3 Rc4 3.Ka2 b4 4.Kb2 b3 5.Rg1 Rc2+ 6.Ka3 Kh2 7.Rf1 Rc4 8.Rf2+ Kg3 9.Rf1 Kg2 10.Rb1 Kf2 11.Rh1 Rc2 12.Kb4 Ke2 13.Rh2+ Ke1 14.Rh1+ Kf2 15.Rd1 Ke2 16.Rb1 Kd3 17.Rd1+ Rd2 18.Rh1 b2 19.Kc5 Kc2 20.Kd5 b1Q 21.Rxb1 Kxb1 22.Ke5 Kb2 23.Kf6 Kc2 24.Kg6 Kd3 25.Kh5 Rh2+ 26.Kg4 Ke3 27.Kg3 Rd2 28.Kg4 Ke4 29.Kg3 Kf5
 51/67-	00:13	 221.602k	16.761k	-47,60	1. ... Rc2+
 51/67-	00:13	 224.436k	16.728k	-47,67	1. ... Rc2+
 51/67-	00:23	 397.711k	17.206k	-101,21	1. ... Rc2+
 51/70	01:02	 1.281.644k	20.592k	-M30	1. ... Rc2+ 2.Ka3 Rc4 3.Rg1 b4+ 4.Ka4 b3+ 5.Ka3 Kh2 6.Rd1 Kg2 7.Rb1 Kf2 8.Rh1 Rc2 9.Kb4 Ke2 10.Rh2+ Ke1 11.Rh1+ Kf2 12.Ra1 Ke3 13.Rh1 b2 14.Ka3 Nf3 15.Rb1 Nd2 16.Rxb2 Nc4+ 17.Kb3 Rxb2+ 18.Kxc4 Rd2 19.Kc5 Ke4 20.Kb4 Rc2 21.Kb3 Rc5 22.Kb4 Kd4 23.Kb3 Rc4 24.Kb2 Kd3 25.Kb3 Rd4 26.Kb2 Rb4+ 27.Ka3 Kc3 28.Ka2 Ra4+ 29.Kb1 Ra3 30.Kc1 Ra1+
 52/70	02:05	 2.849.430k	22.774k	-M29	1. ... b4 2.Rg8 Rc4 3.Rg7 b3 4.Rg1 Kh2 5.Rb1 Kg3 6.Ka3 Kf2 7.Rh1 Rc2 8.Kb4 Ke2 9.Rh2+ Ke1 10.Rh1+ Kf2 11.Ra1 Ke3 12.Rh1 b2 13.Ka3 Nf3 14.Rb1 Nd2 15.Rxb2 Nc4+ 16.Kb3 Rxb2+ 17.Kxc4 Ke4 18.Kc5 Rd2 19.Kc4 Rc2+ 20.Kb3 Rc5 21.Kb4 Kd4 22.Kb3 Kd3 23.Kb4 Rd5 24.Kb3 Rb5+ 25.Ka4 Kc4 26.Ka3 Kc3 27.Ka2 Ra5+ 28.Kb1 Ra4 29.Kc1 Ra1+
 53/70	02:21	 3.266.565k	23.142k	-M28	1. ... b4 2.Rg8 Rc4 3.Rg7 b3 4.Rg1 Kh2 5.Rb1 Kg3 6.Ka3 Kf3 7.Re1 Rc8 8.Rh1 Rc2 9.Kb4 Kf2 10.Ra1 Ke3 11.Rh1 b2 12.Ka3 Nf3 13.Rb1 Nd2 14.Rxb2 Nc4+ 15.Kb3 Rxb2+ 16.Kxc4 Ke4 17.Kc5 Rd2 18.Kc4 Rc2+ 19.Kb3 Rc5 20.Kb4 Kd4 21.Kb3 Kd3 22.Kb4 Rd5 23.Kb3 Rb5+ 24.Ka4 Kc4 25.Ka3 Kc3 26.Ka2 Ra5+ 27.Kb1 Ra4 28.Kc1 Ra1+
 54/70	02:41	 3.764.785k	23.293k	-M28	1. ... b4 2.Rg8 Rc4 3.Rg7 b3 4.Rg1 Kh2 5.Rb1 Kg3 6.Ka3 Kf3 7.Re1 Rc8 8.Rh1 Rc2 9.Kb4 Kf2 10.Ra1 Ke3 11.Rh1 b2 12.Ka3 Nf3 13.Rb1 Nd2 14.Rxb2 Nc4+ 15.Kb3 Rxb2+ 16.Kxc4 Ke4 17.Kc5 Rd2 18.Kc4 Rc2+ 19.Kb3 Rc5 20.Kb4 Kd4 21.Kb3 Kd3 22.Kb4 Rd5 23.Kb3 Rb5+ 24.Ka4 Kc4 25.Ka3 Kc3 26.Ka2 Ra5+ 27.Kb1 Ra4 28.Kc1 Ra1+
 55/70	03:06	 4.373.416k	23.404k	-M28	1. ... b4 2.Rg8 Rc4 3.Rg7 b3 4.Rg1 Kh2 5.Rb1 Kg3 6.Ka3 Kf3 7.Re1 Rc8 8.Rh1 Rc2 9.Kb4 Kf2 10.Ra1 Ke3 11.Rh1 b2 12.Ka3 Nf3 13.Rb1 Nd2 14.Rxb2 Nc4+ 15.Kb3 Rxb2+ 16.Kxc4 Ke4 17.Kc5 Rd2 18.Kc4 Rc2+ 19.Kb3 Rc5 20.Kb4 Kd4 21.Kb3 Kd3 22.Kb4 Rd5 23.Kb3 Rb5+ 24.Ka4 Kc4 25.Ka3 Kc3 26.Ka2 Ra5+ 27.Kb1 Ra4 28.Kc1 Ra1+
 56/70	04:55	 7.018.637k	23.729k	-M27	1. ... b4 2.Rg8 Rc4 3.Rg7 b3 4.Rg1 Kh2 5.Rb1 Kg3 6.Ka3 Kf3 7.Rh1 Rc2 8.Kb4 Kf2 9.Ra1 Ke3 10.Rh1 b2 11.Ka3 Nf3 12.Rb1 Nd2 13.Rxb2 Nc4+ 14.Kb3 Rxb2+ 15.Kxc4 Ke4 16.Kc5 Rd2 17.Kc4 Rc2+ 18.Kb3 Rc5 19.Kb4 Kd4 20.Kb3 Kd3 21.Kb4 Rd5 22.Kb3 Rb5+ 23.Ka4 Kc4 24.Ka3 Kc3 25.Ka2 Ra5+ 26.Kb1 Ra4 27.Kc1 Ra1+
 57/70	07:52	 11.183.781k	23.679k	-M26	1. ... b4 2.Rg8 Rc4 3.Rg7 b3 4.Rg1 Kh2 5.Rb1 Kg3 6.Ka3 Kf3 7.Rh1 Rc2 8.Kb4 Kf2 9.Ra1 Ke3 10.Rh1 b2 11.Ka3 Nf3 12.Rb1 Nd2 13.Rxb2 Nc4+ 14.Kb3 Rxb2+ 15.Kxc4 Ke4 16.Kc5 Rd2 17.Kc4 Rd5 18.Kc3 Rd4 19.Kc2 Rd3 20.Kc1 Ke3 21.Kc2 Ke2 22.Kc1 Rd2 23.Kb1 Kd1 24.Ka1 Kc2 25.Ka2 Rd3 26.Ka1 Ra3+
 58/70	13:20	 19.248.956k	24.048k	-M26	1. ... b4 2.Rg8 Rc4 3.Rg7 b3 4.Rg1 Kh2 5.Rb1 Kg3 6.Ka3 Kf3 7.Rh1 Rc2 8.Kb4 Kf2 9.Ra1 Ke3 10.Rh1 b2 11.Ka3 Nf3 12.Rb1 Nd2 13.Rxb2 Nc4+ 14.Kb3 Rxb2+ 15.Kxc4 Ke4 16.Kc5 Rd2 17.Kc4 Rd5 18.Kc3 Rd4 19.Kc2 Rd3 20.Kc1 Ke3 21.Kc2 Ke2 22.Kc1 Rd2 23.Kb1 Kd1 24.Ka1 Kc2 25.Ka2 Rd3 26.Ka1 Ra3+
 59/70	16:16	 23.469.090k	24.039k	-M26	1. ... b4 2.Rg8 Rc4 3.Rg7 b3 4.Rg1 Kh2 5.Rb1 Kg3 6.Ka3 Kf3 7.Rh1 Rc2 8.Kb4 Kf2 9.Ra1 Ke3 10.Rh1 b2 11.Ka3 Nf3 12.Rb1 Nd2 13.Rxb2 Nc4+ 14.Kb3 Rxb2+ 15.Kxc4 Ke4 16.Kc5 Rd2 17.Kc4 Rd5 18.Kc3 Rd4 19.Kc2 Rd3 20.Kc1 Ke3 21.Kc2 Ke2 22.Kc1 Rd2 23.Kb1 Kd1 24.Ka1 Kc2 25.Ka2 Rd3 26.Ka1 Ra3+
 60/70	16:45	 24.160.009k	24.033k	-M26	1. ... b4 2.Rg8 Rc4 3.Rg7 b3 4.Rg1 Kh2 5.Rb1 Kg3 6.Ka3 Kf3 7.Rh1 Rc2 8.Kb4 Kf2 9.Ra1 Ke3 10.Rh1 b2 11.Ka3 Nf3 12.Rb1 Nd2 13.Rxb2 Nc4+ 14.Kb3 Rxb2+ 15.Kxc4 Ke4 16.Kc5 Rd2 17.Kc4 Rd5 18.Kc3 Rd4 19.Kc2 Rd3 20.Kc1 Ke3 21.Kc2 Ke2 22.Kc1 Rd2 23.Kb1 Kd1 24.Ka1 Kc2 25.Ka2 Rd3 26.Ka1 Ra3+
 61/70	18:52	 27.272.939k	24.076k	-M26	1. ... b4 2.Rg8 Rc4 3.Rg7 b3 4.Rg1 Kh2 5.Rb1 Kg3 6.Ka3 Kf3 7.Rh1 Rc2 8.Kb4 Kf2 9.Ra1 Ke3 10.Rh1 b2 11.Ka3 Nf3 12.Rb1 Nd2 13.Rxb2 Nc4+ 14.Kb3 Rxb2+ 15.Kxc4 Ke4 16.Kc5 Rd2 17.Kc4 Rd5 18.Kc3 Rd4 19.Kc2 Rd3 20.Kc1 Ke3 21.Kc2 Ke2 22.Kc1 Rd2 23.Kb1 Kd1 24.Ka1 Kc2 25.Ka2 Rd3 26.Ka1 Ra3+

[Krzysztof Grzelak]

Please write using what Gui was analyzed position. I used gui Fritz 12 and Shredder Classic 4 and no mat not found. I used 6-men Syzygy tablebases then analyzed without tablebases.