What engine see the Queen Sacrifice of Caruana game vs Naka?

[Dann Corbit]

Here is what I have for the positions discussed in this thread:

[d]1r1qk2r/5p2/p2p1b1p/3NpB2/1P2P2P/8/1PP2B2/2KR3R w k - acd 50; acs 14340; bm Rd3; ce 120; pm Rd3; pv Rd3 Rb5;

[d]8/8/4kpp1/3p1b2/p6P/2B5/6P1/6K1 b - - acd 61; acs 64860; bm Bh3; c0 "level: hard-16"; c1 "diff=7"; c3 "Bh3"; ce 5212; id "Pet.19"; pm Bh3; pv Bh3 g3 Kf5 Kf2 Ke4 Bb2 Bg4 Kg1 Ke3 Kf1 d4 Ke1 Bf3 Ba3 Be4 Bc5 Kd3 Kd1 Bf3+ Kc1 Ke3 Kb2 f5 Ka3 Be2 Kxa4 Kf3 Bxd4 Kxg3 Be5+ Kxh4 Kb4 Kg4 Kc3 g5 Kd2 Bc4 Ke3 f4+ Ke4 Bd5+ Kd4 Bc6 Bc7 Kh3 Ba5 f3 Ke3 Kg2 Be1 Bd7 Bf2 Bb5 Be1 Bc6 Bf2 Bd7 Be1 g4 Bh4 Be6 Kd4 f2 Kc;

[d]r1b1k2r/2q1bp2/p2p1n1p/4p3/1P1NPQBP/2N5/1PP2B2/2KR3R w kq - acd 49; acs 14340; bm Qxf6; ce 112; pm Qxf6; pv Qxf6;

[d]r1bqk2r/5p2/p2p1b1p/3Np3/1P1NP1BP/8/1PP2B2/2KR3R w kq - acd 48; acs 14340; bm Nf5; c3 "Nf5"; ce 117; pm Nf5; pv Nf5 Bxf5 Bxf5 Rb8 Rd3 Bg7 h5 Rb5 Kb1 O-O Bh4 Rxd5 Bxd8 Rxd3 Be7 Rf3 Bxf8 Bxf8 Rg1+ Kh8 Rd1 d5 Rxd5 Bxb4 c3 Bf8 Rxe5 Bd6 Rd5 Bg3 c4 Kg7 Ka2 Rf2 Ka3 Rf1 b3 Kf6 Kb4 Be1+ Ka4 Bg3 Ka5 Rf3 Kb4 Re3 c5 a5+ Ka4 Rc3 Bc8 Re3 Bb7 Rxe4+ Kxa5 Ke7 Kb5;

[Dicaste]

Hello Eren, I don't know M8R but thanks for the analysis! Here c4 seems edged out just a little by Kb1 at depth 25 and 26 but very close. Program has a lot of hash knowledge at this point, but mainly after Kb1 Be7 (I think the rest has been wiped out because I went to the very end of the Kb1 Be7 line and left program running for several hours then back) so after Kb1 O-O eval is lower.


[D]1r1qk2r/5p2/p2p1b1p/3NpB2/1P2P2P/8/1PP2B2/2KR3R w k -

Engine: Rainbow Serpent 20160903_016 HT (7 threads, 512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott

26 2:57 +1.67 23.Kb1 O-O 24.Rdg1+ Kh8 25.Be3 Bg7
26.Rh3 Rg8 27.Rhg3 Qe8 28.c3 Qd8
29.c4 a5 30.b5 Qf8 31.Kc2 Rd8
32.Bxh6 Bxh6 33.Rxg8+ Qxg8 34.Rxg8+ Kxg8
35.b6 Kf8 36.Kb3 (1.701.389.783) 9587

26 2:57 +1.65 23.c4 a5 24.b5 Bg7 25.Rdg1 O-O 26.h5 a4
27.Bh4 f6 28.Rg6 Rb7 29.Bxf6 Rxf6
30.Nxf6+ Kh8 31.Nd5 a3 32.bxa3 Qa5
33.Rg3 Qa7 34.Rc3 Qf2 35.Kb1 Bf8
36.Rhc1 (1.701.389.783) 9587

26 2:57 +0.39 23.Rd3 Rb5 24.c4 Rxd5 25.Rxd5 Qb8
26.c5 Be7 27.Kb1 Qxb4 28.cxd6 Bxd6
29.Rhd1 Be7 30.Rxe5 f6 31.Bc5 Qxc5
32.Bg6+ Kf8 33.Rxc5 Bxc5 34.Rd7 h5
35.Rf7+ Kg8 36.Rxf6 (1.701.389.783) 9587

26 2:57 0.00 23.Rh2 Rb5 24.Rh3 O-O 25.Be3 Rxd5
26.Rxd5 Bxh4 27.Kb1 Kg7 28.Bc5 Be7
29.Rg3+ Kh8 30.Rh3 Kg7 (1.701.389.783) 9587

26 2:57 0.00 23.Rh3 Rg8 24.Rc3 Bxh4 25.Ba7 Bg5+
26.Kb1 Rb7 27.Bf2 Rb8 28.Ba7 (1.701.389.783) 9587

Sorry but i am not a good player too 1850 elo only. I am try to dig up position but couldn't get why Kb1 is necessary. I stil think c4 is better in here. I am just tried long search 5:30 minutes and M8R still with me.

Code: Select all

FEN: 1r1qk2r/5p2/p2p1b1p/3NpB2/1P2P2P/8/1PP2B2/2KR3R w k - 0 1

M8R x64:
 8-	00:00	 31k	3.846k	-0,42	Rdg1 Rb5
 8	00:00	 51k	3.606k	-0,37	Rh2 Rg8 c3 Be7 Kb1 a5 Ba7 Rb7
 9-	00:00	 53k	3.553k	-0,46	Rh2 Rg8
 9-	00:00	 56k	3.516k	-0,45	Rdg1 Rb5
 9-	00:00	 58k	3.416k	-0,54	Rdg1 Rb5
 9-	00:00	 63k	3.311k	-0,53	c3 Rg8
 9-	00:00	 74k	3.094k	-0,65	c3 Rg8
 9	00:00	 77k	2.962k	-0,62	Rdg1 Rb5 Rh3 Rxd5 exd5 Qb8 c3 Qb5 Bd3 Qxd5
 9+	00:00	 87k	2.817k	-0,45	Be3 Rg8 Bxh6
 9-	00:00	 94k	2.762k	-0,55	Be3 Bxh4
 9+	00:00	 95k	2.784k	-0,22	Rh2 Be7 c4
 9	00:00	 101k	2.797k	-0,19	Rh2 Be7 c4 Rg8 Kb1 Kf8 Ba7 Rb7 Be3
 10-	00:00	 103k	2.700k	-0,26	Rh2 Be7
 10	00:00	 109k	2.655k	-0,32	Rh2 Be7 c4 Kf8 Kb1 Rg8 Ba7 Rb7 Be3 h5
 11-	00:00	 140k	2.592k	-0,39	Rh2 Be7
 11-	00:00	 147k	2.547k	-0,46	Rh2 Be7
 11	00:00	 148k	2.557k	-0,40	c4 Rg8 Rh2 Rb7 Kc2 Be7 Ra1 Qb8 b3 Qa8 Kb2 Bd8
 12+	00:00	 154k	2.538k	-0,33	c4 Rg8 Rh2
 12	00:00	 160k	2.518k	-0,39	c4 Rg8 Rh2 Kf8 Kc2 Be7 Ra1 Rc8 b3 Rc6 Be3 Bxh4 Bxh6+ Ke8
 12+	00:00	 166k	2.525k	-0,26	Rh2 Be7 Rd3
 12-	00:00	 169k	2.523k	-0,38	Rh2 Be7
 12+	00:00	 174k	2.537k	-0,24	Rh2 Be7 Rd3
 12-	00:00	 192k	2.477k	-0,38	Rh2 Be7
 12+	00:00	 259k	2.384k	-0,20	Rh2 Rg8 c4
 12	00:00	 260k	2.395k	-0,38	Rh2 Rg8 c4 Rb7 Kc2 Be7 Be3 h5 Ra1 Qb8 Bd2 Rg3 Rxa6
 12	00:00	 361k	2.641k	-0,15	Kb1 Kf8 c4 Be7 Rdg1 h5 Be3 Bxh4 c5 dxc5 bxc5 Rb5 c6
 13+	00:00	 395k	2.623k	-0,08	Kb1 Kf8 c4
 13+	00:00	 445k	2.557k	-0,01	Kb1 Kf8 c4
 13-	00:00	 460k	2.484k	-0,08	Kb1 Rg8
 13	00:00	 490k	2.464k	-0,11	Kb1 h5 Rd3 Rg8 Rh2 Rb5 c4 Rxd5 Rxd5 Be7 c5 Qc7 Be3 Qa7 Bf2 Qb8
 14-	00:00	 507k	2.442k	-0,18	Kb1 h5
 14	00:00	 598k	2.561k	-0,15	Kb1 h5 Rd3 Rg8 Rh2 Rb5 c4 Rxd5 Rxd5 Be7 c5 Qb8 c6 Bd8 b5 axb5 Be3 Be7 Bd7+ Kd8
 15	00:00	 639k	2.591k	-0,18	Kb1 h5 Rd3 Rg8 Rh2 Rb5 c4 Rxd5 Rxd5 Be7 c5 Qb8 c6 Bd8 Be3 Qxb4 Rc2 Rg3 Bf2
 16-	00:00	 688k	2.624k	-0,24	Kb1 h5
 16+	00:00	 934k	2.750k	-0,12	c4 Rg8 Rh2
 16+	00:00	 966k	2.743k	-0,06	c4 Rg8 Rh2
 16-	00:00	 1.045k	2.763k	-0,12	c4 Rg8
 16+	00:00	 1.206k	2.793k	-0,04	c4 Rg8 Rh2
 16	00:00	 1.313k	2.821k	 0,00	c4 Rg8 Rh2 h5 Kc2 Be7 Ra1 Kf8 Rxa6 Ra8 b5 Rxa6 bxa6 Qa5 a7 Qa4+ Kb1 Qd1+ Ka2 Qa4+ Kb1
 17	00:00	 1.478k	2.871k	 0,00	c4 Rg8 Rh2 h5 Kc2 Be7 Ra1 Kf8 Rxa6 Ra8 b5 Rxa6 bxa6 Qa5 a7 Qa4+ Kb1 Qd1+ Ka2 Qa4+ Kb1
 18	00:00	 1.630k	2.920k	 0,00	c4 Rg8 Rh2 h5 Kc2 Kf8 Ra1 Be7 Rxa6 Ra8 b5 Rxa6 bxa6 Qa5 a7 Qa4+ Kb1 Qd1+ Ka2 Qa4+ Kb1
 19	00:00	 2.292k	3.401k	 0,00	c4 Rg8 Rh2 h5 Kc2 Kf8 Ra1 Be7 Rxa6 Ra8 b5 Rxa6 bxa6 Qa5 a7 Qa4+ Kb1 Qd1+ Ka2 Qa4+ Kb1
 20	00:00	 3.331k	3.532k	 0,00	c4 Be7 Kc2 Kf8 Ra1 Rg8 Rh2 h5 Rxa6 Ra8 b5 Rxa6 bxa6 Qa5 a7 Qa4+ Kb1 Qd1+ Ka2 Qa4+ Kb1
 21+	00:01	 4.788k	3.628k	+0,06	c4 Be7 Kb1
 21+	00:01	 5.784k	3.600k	+0,12	c4 Be7 Kb1
 21+	00:01	 6.400k	3.529k	+0,21	c4 Be7 Kb1
 21-	00:02	 8.389k	3.509k	+0,13	c4 a5
 21+	00:02	 9.209k	3.536k	+0,23	c4 a5 c5
 21-	00:03	 11.705k	3.563k	+0,08	c4 a5
 21	00:03	 11.863k	3.568k	 0,00	c4 a5 c5 Rxb4 Nxb4 axb4 Rxd6 Qa8 Kd2 Be7 Bd7+ Kf8 Rc6 Qa7 Bf5 Qa2 Rc8+ Kg7 Rg1+ Bg5+ hxg5 Qxb2+ Ke3 Qa3+ Kd2 Qa2+ Ke1 Qa1+ Kd2 Qb2+
 22	00:03	 14.392k	3.639k	 0,00	c4 a5 c5 Rxb4 Nxb4 axb4 Rxd6 Qa8 Kd2 Be7 Bd7+ Kf8 Rc6 Qa7 Bf5 Qa2 Rc8+ Kg7 Rg1+ Bg5+ hxg5 Qxb2+ Ke3 Qa3+ Kd2 Qa2+ Ke1 Qa1+ Kd2 Qa2+
 23+	00:04	 15.559k	3.600k	+0,06	c4 a5 c5
 23+	00:04	 16.560k	3.607k	+0,12	c4 a5 c5
 23-	00:04	 16.812k	3.600k	+0,06	c4 a5
 23+	00:05	 18.314k	3.613k	+0,13	c4 a5 c5
 23+	00:07	 25.248k	3.479k	+0,32	c4 a5 b5
 23-	00:07	 25.886k	3.470k	+0,17	c4 a5
 23	00:08	 28.502k	3.474k	+0,22	c4 a5 b5 Rg8 Rh2 Be7 b6 Kf8 Be3 Rg3 Bxh6+ Kg8 Bd2 a4 Be1 Rb3 Bc3 a3 c5 axb2+ Bxb2 Bxh4 c6 R8xb6 c7 Rc6+ Kb1 Rxc7 Nxc7 Qxc7 Rxh4
 24+	00:08	 30.729k	3.465k	+0,28	c4 a5 b5
 24-	00:08	 31.164k	3.465k	+0,22	c4 a5
 24+	00:09	 33.488k	3.459k	+0,28	c4 a5 b5
 24	00:09	 34.198k	3.466k	+0,25	c4 a5 b5 Rg8 Rh2 Be7 b6 Kf8 Be3 Rg3 Bxh6+ Kg8 Be3 Rxe3 Rg2+ Kh8 Nxe3 Qf8 Nd5 Bd8 Kb1 Bxb6 Nf6 Qh6 Nd7 Rb7 Nxb6 Rxb6 c5 Rb4 cxd6 Qxh4 d7
 25+	00:10	 36.531k	3.471k	+0,31	c4 a5 b5
 25+	00:10	 37.893k	3.477k	+0,37	c4 a5 b5
 25+	00:12	 41.697k	3.459k	+0,46	c4 a5 b5
 25-	00:12	 43.171k	3.456k	+0,38	c4 a5
 25+	00:13	 46.916k	3.476k	+0,48	c4 a5 b5
 25+	00:17	 62.869k	3.551k	+0,76	c4 a5 b5
 25-	00:17	 63.244k	3.553k	+0,54	c4 a5
 25	00:18	 65.140k	3.559k	+0,46	c4 a5 b5 Kf8 b6 Be7 Nxe7 Kxe7 c5 Rg8 h5 Rg2 Bh4+ f6 Rxd6 Qg8 Re6+ Qxe6 Bxe6 Kxe6 Rd1 Ke7 Rd6 Rg1+ Kd2 Rf1 Ke3 Rf4 Bf2 Rc8 b7 Rb8 Rb6 Kd8 Bg3 Rg4 Kf3 Rg8 Rd6+ Kc7 Rxf6 Rg5 c6
 26+	00:20	 71.745k	3.556k	+0,52	c4 a5 b5
 26+	00:20	 72.795k	3.560k	+0,58	c4 a5 b5
 26+	00:21	 75.878k	3.563k	+0,67	c4 a5 b5
 26-	00:21	 77.246k	3.565k	+0,59	c4 a5
 26+	00:22	 79.782k	3.570k	+0,69	c4 a5 b5
 26	00:25	 92.052k	3.563k	+0,85	c4 Be7 Kb1 Rg8 Rdg1 Rf8 Be3 Rh8 Rg2 Bf8 h5 a5 b5 a4 Bd2 Rb7 Rhg1 Qh4 Be1 Qd8 Rg8 Rxg8 Rxg8 Ra7 Bd2 a3 b6 a2+ Ka1
 27+	00:30	 108.645k	3.562k	+0,91	c4 Be7 Kb1
 27+	00:33	 118.729k	3.584k	+0,97	c4 Be7 Kb1
 27-	00:35	 127.942k	3.616k	+0,91	c4 Be7
 27+	00:39	 146.091k	3.665k	+0,98	c4 Be7 Kb1
 27+	00:45	 168.844k	3.681k	+1,17	c4 a5 b5
 27	00:48	 179.166k	3.683k	+1,07	c4 a5 b5 Kf8 b6 Be7 Kb1 Qe8 Nxe7 Kxe7 c5 Qb5 Rd5 Kf6 Rc1 Qe2 Rxd6+ Kg7 Bg3 Rhe8 h5 Qxh5 Rd5 Qe2 Bxe5+ Rxe5 Rxe5 a4 Rd5 a3 bxa3 h5 Rc2 Qe3 Kb2 h4 a4 Qg3 Rc3 Qe1 Kb3
 28-	00:48	 180.485k	3.684k	+1,01	c4 a5
 28-	00:49	 181.167k	3.686k	+0,95	c4 a5
 28-	00:49	 183.549k	3.694k	+0,86	c4 a5
 28	00:55	 204.188k	3.700k	+0,87	c4 Rb7 Kb1 h5 c5 dxc5 bxc5 Rc7 Nxc7+ Qxc7 Rd6 Be7 Rxa6 Qd8 Kc2 Rg8 Rd1 Qb8 Rc6 Rg2 Rd2 Rxf2 Rxf2 Bxh4 Rh2 Qb5 Rc8+ Ke7 Rxh4 Qe2+ Kb3 Qd1+ Kc4 Qf1+ Kd5 Qd3+ Kxe5 Qg3+ Kd4 Qxh4
 29+	00:57	 213.637k	3.720k	+0,93	c4 Rb7 Kb1
 29+	00:58	 219.291k	3.730k	+0,99	c4 Rb7 Kb1
 29+	00:59	 223.298k	3.733k	+1,08	c4 Rb7 Kb1
 29-	01:03	 238.749k	3.739k	+1,00	c4 Bg7
 29+	01:07	 251.871k	3.742k	+1,10	c4 Bg7 h5
 29-	01:09	 258.756k	3.737k	+0,95	c4 a5
 29	01:10	 264.653k	3.738k	+0,93	c4 a5 b5 Kf8 b6 Be7 Kb1 Qe8 Nxe7 Kxe7 c5 Qb5 Rd5 Kf6 Rc1 Qe2 Rxd6+ Kg7 Bg3 Rhe8 h5 Qxh5 Rd5 Qe2 Bxe5+ Rxe5 Rxe5 h5 Rd5 h4 Rg1+ Kf8 Rgd1 Qb5 R1d3 a4 Kc2 Kg7 Rc3 a3 bxa3 Rh8 Rd1 Qa4+ Kc1
 30-	01:11	 267.840k	3.742k	+0,87	c4 a5
 30+	01:16	 286.675k	3.758k	+0,93	c4 a5 b5
 30+	01:19	 298.368k	3.762k	+1,02	c4 a5 b5
 30-	01:19	 300.638k	3.762k	+0,94	c4 a5
 30+	01:27	 329.006k	3.779k	+1,04	c4 a5 b5
 30	01:46	 402.950k	3.774k	+1,24	c4 a5 b5 0-0 Be3 Bg7 Rdg1 Kh8 Bg5 f6 Be3 Rf7 Rg6 Qf8 Kc2 a4 h5 Rc8 Kc3 Rb8 Ra1 Ra8 Kc2 Rb7 Ra3 Rf7 Kb1 Rb7 Bd2 Rf7 Kc1 Rb7 Kc2 Rbb8 Be3 Rb7
 31-	01:47	 404.761k	3.775k	+1,18	c4 a5
 31-	01:55	 438.107k	3.789k	+1,12	c4 Be7
 31-	01:58	 450.887k	3.797k	+1,03	c4 Be7
 31+	02:08	 488.808k	3.804k	+1,10	c4 Be7 Kb1
 31+	02:27	 564.614k	3.818k	+1,29	c4 Be7 Kb1
 31-	02:42	 621.415k	3.817k	+1,14	c4 Bg7
 31	02:46	 635.533k	3.806k	+1,23	c4 Bg7 h5 Rb7 Bh4 f6 Rhg1 0-0 Rg6 Kh8 Bf2 Rff7 Rdg1 Qf8 Bh4 a5 b5 a4 R1g3 Qa8 Be6 Qa5 Rc3 Rf8 Bf2 Rfb8 Bf5 Rg8 Kc2 Qa8 Ra3 Rc8 Bxc8 Qxc8 Rc3 f5 Rxd6 fxe4
 32+	02:57	 674.094k	3.800k	+1,29	c4 Bg7 h5
 32-	02:58	 677.672k	3.801k	+1,23	c4 Bg7
 32-	03:01	 690.982k	3.808k	+1,14	c4 Bg7
 32+	03:13	 740.208k	3.825k	+1,21	c4 Bg7 h5
 32	03:21	 770.240k	3.817k	+1,25	c4 Bg7 h5 Rb7 Bh4 f6 Bg6+ Rf7 Bxf7+ Kxf7 b3 Rf8 Rhf1 Qd7 Rf5 Kg8 Rg1 Qa7 Bf2 Qb7 Kb2 Kh7 Rg6 Rf7 Be3 Qd7 Rg1 Kh8 Kc3 Qc8 Rg3 Qb7 Kb2 Kh7 Rg1 Qd7 Rg6 Qb7
 33+	03:37	 829.010k	3.820k	+1,31	c4 Bg7 h5
 33-	03:40	 840.523k	3.818k	+1,25	c4 Bg7
 33	04:02	 922.821k	3.802k	+1,17	c4 Bg7 h5 Rb7 Bh4 f6 Bg6+ Rf7 Bxf7+ Kxf7 b3 Rf8 Rhf1 Qd7 Rf5 Kg8 Rg1 Qa7 Bf2 Qb7 Kb2 Kh7 Rg6 Qb8 Be3 Qc8 Bb6 Rf7 Bf2 Qb8 Rg1 Qc8 Be3 Qe8 Rg6 Qa8 Rg3
 34+	04:37	 1.057.881k	3.805k	+1,23	c4 Bg7 h5
 34+	04:49	 1.099.251k	3.793k	+1,29	c4 Bg7 h5
 34+	05:05	 1.151.951k	3.775k	+1,38	c4 Bg7 h5
 34	05:18	 1.200.940k	3.768k	+1,47	c4 Bg7 h5 Rb7 Kb1 0-0 Rdg1 Kh8 Bh4 f6 Rg6 a5 b5 a4 Be1 Rff7 Bd2 Qf8 Rh3 Ra7 Rhg3 Ra8 Ra3 Rfa7 Kc2 Rb7 Be3 Rf7 Ra1 Rb7 Kc3 Qd8 Bxh6 a3 Rxa3 Rxa3+ bxa3 Bxh6 Rxh6+ Kg8

for M8R difference is 0.10 between c4 and Kb1.

[Eelco de Groot]

Hello, yes, you are probably right, Eren, for some strange reason it was missed by Rainbow Serpent. Even stranger perhaps that it should be missed with 7 threads, where you'd expect the search to be wider a bit than with 4 threads. Even stranger on a search 200 times as long as with M8R. I have never heard of your program before?

Even stranger perhaps then Dann's output for the position. If this is Stockfish or something like it we definitely have a bug, somewhere? But what it is I don't know.

Here is what I have for the positions discussed in this thread:

[d]1r1qk2r/5p2/p2p1b1p/3NpB2/1P2P2P/8/1PP2B2/2KR3R w k - acd 50; acs 14340; bm Rd3; ce 120; pm Rd3; pv Rd3 Rb5;

Here is my Multi PV 5:


1r1qk2r/5p2/p2p1b1p/3NpB2/1P2P2P/8/1PP2B2/2KR3R w k -

Engine: Rainbow Serpent 20160903 HT (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G.

41 965:59 +3.10 23.c4 a5 24.b5 Kf8 25.b6 Be7 26.Kb1 a4
27.Nxe7 Kxe7 28.c5 Rg8 29.h5 Rg2
30.Bh4+ f6 31.Rhf1 Rxb6 32.cxb6 Qxb6
33.Bxf6+ Kxf6 34.Bh3+ Kg5 35.Bxg2 a3
36.Rd2 (541.840.165.733) 9348

41 965:59 +2.43 23.Kb1 O-O 24.Be3 Bg7 25.Rdg1 Kh8
26.Rh3 Rg8 27.Rhg3 Rb5 28.c4 Rxd5
29.cxd5 Qb8 30.b3 Qa8 31.Bd2 Qe8
32.Kb2 Qa8 33.Ka2 Qf8 34.R1g2 Qd8
35.Kb1 Qa8 36.Kc2 (541.840.165.733) 9348

41 965:59 +1.93 23.Rd3 Rb5 24.c4 Rxd5 25.Rxd5 Be7
26.c5 Qb8 27.Rhd1 dxc5 28.bxc5 O-O
29.Be3 Kh8 30.Kb1 Qb5 31.Bxh6 Rb8
32.Bc1 a5 33.R1d2 a4 34.Rc2 Qc6
35.Bd7 Qc7 36.Bd2 (541.840.165.733) 9348

41 965:59 +0.79 23.Rh3 Be7 24.Rdh1 Rb5 25.Rc3 Rxd5
26.exd5 O-O 27.Rg1+ Kh8 28.Be3 Bxh4
29.Bxh6 Rg8 30.Rxg8+ Qxg8 31.Rc8 Bd8
32.Kb1 e4 33.Bxe4 Qe8 34.Bd3 Qe1+
35.Ka2 Qh4 36.Bd2 (541.840.165.733) 9348

41 965:59 +0.76 23.Rd2 a5 24.bxa5 Qxa5 25.Nxf6+ Kf8
26.Rdd1 Qa1+ 27.Kd2 Qa5+ 28.Ke2 Rxb2
29.Kf3 Qc3+ 30.Be3 Qxc2 31.Rd2 Qxd2
32.Bxd2 Rxd2 33.Rb1 Ke7 34.Nh7 d5
35.Rb7+ Kd6 36.Nf6 (541.840.165.733) 9348

best move: c2-c4 time: 1001:14.703 min n/s: 9.348.666 nodes: 563.196.858.381

[tpoppins]

A couple more entries for Dann's db as well as the fans of trillion-plus-nodes analyses.

Caruana - Nakamura, London Classic (r6.3) 2016
[d]r1bqk2r/5p2/p2p1b1p/3NpN2/1P2P1BP/8/1PP2B2/2KR3R b kq - 0 21
(pos after 21.Nf5)

Analysis by Stockfish 221216 x64 POPCNT:

Code: Select all

1. +- (2.43): 21...Bxf5 22.Bxf5 Be7 23.Rd3 Rb8 24.Rc3 Kf8 25.Kb1 Rg8 26.Be3 Rh8 27.Rc7 Rxb4 28.Rxe7 Qxe7 29.Nxe7 Kxe7 30.b3 h5 31.Bg5+ f6 32.Bd2 Rbb8 33.Rh3 Rb5 34.Rg3 Kf7 35.Bd7 Rc5 36.Bb4 Rc7 37.Bh3 Rc6 38.Bf5 Rb6 39.Ba3 Rc6 40.Kb2 Rb8 41.Bg6+ Ke7 42.Bxh5 Rh8 43.Rg7+ Kd8 44.Bf7 Rxh4 45.Bd5 Rc7 46.Rg8+ Ke7 47.Bb4 Rh2 48.Rg7+ Kd8 49.Ba5 Rhxc2+ 50.Ka3 Rc1 51.Kb4 R1c5 52.Bxc7+ Rxc7 53.Rg8+ Ke7 54.Ra8 a5+ 55.Rxa5 
2. +- (2.81): 21...Rb8 22.Nxf6+ Qxf6 23.Nxd6+ Qxd6 24.Rxd6 Bxg4 25.Bc5 Ra8 26.Rf1 Rd8 27.Rb6 Rg8 28.Rxh6 Be2 29.Re1 Bc4 30.b3 Be6 31.Rh5 Rd7 32.Rf1 Rd8 33.Rh1 Rd7 34.Rxe5 Rg2 35.Be3 Rc7 36.Rc5 Rxc5 37.Bxc5 f6 38.h5 Kf7 39.h6 Rg8 40.Bd4 Kg6 41.h7 Rh8 42.Rf1 Kxh7 43.Rxf6 Re8 44.e5 Bc8 45.Kd2 Kg8 46.c4 Re6 47.Rf4 Bd7 48.Kd3 Re8 49.Rf6 Re6 50.Rf2 Re8 51.Ke4 Rf8 52.Rg2+ Kf7 
  Depth: 51/98  18:44:27  981667 MN, tb=114421503

Search terminated at a little over 24 hrs. That produced a surpise: 21...Rb8 (described earlier in this thread as a blunder) moved up to #1:

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21...Rb8 22.Nxf6+ Qxf6 23.Nxd6+ Qxd6 24.Rxd6 Bxg4 25.Bc5 Ra8 26.Rf1 Rd8 27.Rb6 Rg8 28.Rxh6 Bh3 29.Rh1 Be6 30.Rh5 Rd7 31.Rxe5 Rg2 32.Be3 Rc7 33.Rc5 Rxc5 34.Bxc5 f6 35.h5 Kf7 36.h6 Rg8 37.Kd2 Rd8+ 38.Ke3 Rh8 39.Kd3 Kg6 40.Be3 Rd8+ 41.Bd4 Rd7 42.c4 f5 43.exf5+ Bxf5+ 44.Kc3 Rf7 45.Ra1 Bc8 46.Bg7 Kh7 47.c5 Re7 48.Rf1 Bd7 49.Rf6 Re6 50.Rf7 Be8 51.Ra7 Bb5 52.Kd4 Re8 53.Rf7 Rd8+ 54.Ke5 Rd2 55.Bf8+ Kh8 56.Rf6 Re2+ 57.Kd4
  +- (3.11)  Depth: 52/98   24:24:14  1283307 MN, tb=169741885

Second PV remained unresolved at 51/98 and matches the 21...Bxf5 line above, down to the 2.43 eval. That may mean one of three things:

a) 21...Bxf5 is as bad as 21...Rb8, if not worse
b) there's a bug with PV ordering in Multi-PV in SF when one PV is resolved and another is not
c) a misunderstanding on my part

A couple of plies later, after the hypothetically superior 21...Bxf5:

[d]1r1qk2r/5p2/p2p1b1p/3NpB2/1P2P2P/8/1PP2B2/2KR3R w k - 0 1

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Analysis by Houdini 5.01 Pro x64-popc:

1. +- (2.35): 1.c4 a5 2.b5 Rb7 3.b6 0-0 4.c5 dxc5 5.Bxc5 Bg7 6.Kb1 a4 7.Bxf8 Bxf8 8.Rc1 Rxb6 9.Rc8 Qxc8 10.Bxc8 Rb8 11.Bg4 a3 12.Rh2 Kg7 13.Bh5 Bc5 14.Rg2+ Kf8 15.Nf6 Rb7 16.Bd1 axb2 17.Rg8+ Ke7 18.Nd5+ Kd6 19.Rd8+ Rd7 20.Rh8 Bf2 21.Rxh6+ Kc5 22.Bg4 Ra7 23.Kxb2 Kc4 24.h5 Bd4+ 25.Kc2 Ra2+ 26.Kd1 Bc5 27.Rc6 Kd4 28.Nf6 Rh2 29.Be2 Rh4 30.Rc8 
2. +- (1.89): 1.Rd3 Bg7 2.Rg1 Bf6 3.Rdg3 Rf8 4.Rc3 Bxh4 5.Ba7 Bg5+ 6.Kb1 Rb7 7.Bf2 Rb8 8.Rc7 Rh8 9.Ba7 Rxb4 10.c3 Rb5 11.Rc8 Kf8 12.Rxd8+ Bxd8 13.Bc8 a5 14.Ba6 Rxd5 15.exd5 Bg5 16.Kc2 Ke7 17.Bd3 Ra8 18.Bb6 a4 19.Be4 Ra6 20.Bf2 Ra8 21.Bf5 Kf6 22.Bd7 h5 23.Bb6 Bf4 24.Rh1 Ke7 25.Bf5 a3 26.bxa3 Rxa3 27.Kd3 e4+ 28.Kxe4 Be5 29.Rxh5 Rxc3 30.Be3 
  Depth: 42/101  11:44:21  1466108 MN, tb=18233700

Here, too, c4 appears to be the most incisive. Otherwise Black plays ...Rb5 and gets rid of the "eternal knight" on d5. Still in a bad way but can breathe a little easier.

Here is what I have for the positions discussed in this thread:
...
[d]8/8/4kpp1/3p1b2/p6P/2B5/6P1/6K1 b - - acd 61; acs 64860; bm Bh3; c0 "level: hard-16"; c1 "diff=7"; c3 "Bh3"; ce 5212; id "Pet.19"; pm Bh3; pv Bh3 g3 Kf5 Kf2 Ke4 Bb2 Bg4 Kg1 Ke3 Kf1 d4 Ke1 Bf3 Ba3 Be4 Bc5 Kd3 Kd1 Bf3+ Kc1 Ke3 Kb2 f5 Ka3 Be2 Kxa4 Kf3 Bxd4 Kxg3 Be5+ Kxh4 Kb4 Kg4 Kc3 g5 Kd2 Bc4 Ke3 f4+ Ke4 Bd5+ Kd4 Bc6 Bc7 Kh3 Ba5 f3 Ke3 Kg2 Be1 Bd7 Bf2 Bb5 Be1 Bc6 Bf2 Bd7 Be1 g4 Bh4 Be6 Kd4 f2 Kc;

That's not a -52.12 position, it's forced mate for Black. I'll post the back-solved solution as well as deep analysis at the root in the corresponding thread.

[MikeB]

...

Here is what I have for the positions discussed in this thread:
...
[d]8/8/4kpp1/3p1b2/p6P/2B5/6P1/6K1 b - - acd 61; acs 64860; bm Bh3; c0 "level: hard-16"; c1 "diff=7"; c3 "Bh3"; ce 5212; id "Pet.19"; pm Bh3; pv Bh3 g3 Kf5 Kf2 Ke4 Bb2 Bg4 Kg1 Ke3 Kf1 d4 Ke1 Bf3 Ba3 Be4 Bc5 Kd3 Kd1 Bf3+ Kc1 Ke3 Kb2 f5 Ka3 Be2 Kxa4 Kf3 Bxd4 Kxg3 Be5+ Kxh4 Kb4 Kg4 Kc3 g5 Kd2 Bc4 Ke3 f4+ Ke4 Bd5+ Kd4 Bc6 Bc7 Kh3 Ba5 f3 Ke3 Kg2 Be1 Bd7 Bf2 Bb5 Be1 Bc6 Bf2 Bd7 Be1 g4 Bh4 Be6 Kd4 f2 Kc;

That's not a -52.12 position, it's forced mate for Black. I'll post the back-solved solution as well as deep analysis at the root in the corresponding thread.

Aristides finds mate without backsolving in about 4-5 hours on my machine. Just kicked it off again and will post later.

[Dicaste]

I am glad to see that. I think stockfish after a little search it just sticks one move for too long. Looks like rainbow serpent doesn't have that behavior. By the way M8R is my private engine so its quite normal nobody knows.