Old position I posted a while back

[acase]

Thanks Andrew, this does not seem very difficult for almost default Stockfish development version

Hello Eelco,

Thanks for your fast reply.
What do you mean by "almost default Stockfish development version"?

Do you mean that you modified the code slightly? or do you mean you changed the default engine settings?


My Stockfish DV 8/19/2017 with default settings finally gets this one after a little more than 27 minutes:


24.Bc7 Rd7 25.Be4 Qg8 26.Bxd5 exd5 27.Rxd5 Rxd5 28.Qxd5 a4 29.bxa4 bxa4 30.Bd6 Bc3 31.Ra2 Bxf6 32.Be5 Kg7 33.Bxf6+ Kxf6 34.Qxc5 Qc8 35.Qxc8 Rxc8 36.Rxa4 h5 37.Kg2 Rc3 38.Ra6+ Kf5 39.Ra5+ Kg6 40.Rd5 Rb3 41.h4 Kh6 42.Rf5 Kg6 43.Rg5+ Kh6 44.Rd5 Kg6 45.Kg1 Rb1+ 46.Kh2 f6 47.Kg2 Rb3 48.Rd2 Rb5 49.f3 Kf5 50.Rc2 Kg6 51.Kf2 Kf5 52.Ke3 Rb3+ 53.Ke2 Rb5
+/- (0.80) Depth: 49/72 00:20:57 40336MN
24.Rxd5
+/- (0.87 ++) Depth: 50/67 00:27:17 52764MN
24.Rxd5
+/- (0.95 ++) Depth: 50/67 00:29:43 57483MN
24.Rxd5
+/- (1.06 ++) Depth: 50/67 00:31:49 61560MN
24.Rxd5
+/- (1.22 ++) Depth: 50/67 00:34:11 66196MN
24.Rxd5
+/- (1.44 ++) Depth: 50/67 00:37:20 72317MN
24.Rxd5
+- (1.73 ++) Depth: 50/67 00:42:07 81621MN
24.Rxd5
+- (2.11 ++) Depth: 50/82 00:54:04 105335MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rd7 Ba5 63.Rd6+ Kg7 64.Kf5 Be1
+- (2.32) Depth: 50/91 01:10:13 137959MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rb4 Bf6 63.Rb6 Kg7 64.Kd5 Bd8
+- (2.32) Depth: 51/82 01:11:21 140229MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rb5 Bf6 63.Rb6 Kg7 64.Ra6 h5 65.Rd6 Bc3 66.Kf5 h4
+- (2.32) Depth: 52/86 01:12:51 143280MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rb5 Bf6 63.Rb6 Kg7 64.Ra6 Kg6 65.Rc6 Kg7 66.Rc8 Be7 67.Ke3 Kf6
+- (2.32) Depth: 53/88 01:14:03 145744MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf5 Ba3 64.Rc7 Bb2 65.Kg5 Bf6+ 66.Kg4 Kf8 67.Kf3 Bg7 68.Rb7
+- (2.32) Depth: 54/90 01:16:04 149818MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf5 h6 64.Rd7 Bb4 65.Rd3 Be1 66.Rb3 Bd2 67.Ke4 Kf6 68.Rb5
+- (2.32) Depth: 55/103 01:18:18 154333MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf5 h6 64.Rb6 Bc5 65.Rb3 Bd4 66.Rd3 Bc5 67.Ke5 Bf2 68.Kf5 Be1 69.Rb3
+- (2.32) Depth: 56/91 01:24:06 166203MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf3 Bc5 64.Rd7 Bg1 65.Ke4 Kf8 66.Rd8+ Kg7 67.Rb8 Kf6 68.Rg8 Bb6 69.Rb8 Bc7
+- (2.32) Depth: 57/92 01:27:16 172572MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rg5+ Kf6 63.Rf5+ Kg7 64.Kd3 Bd6 65.Ke3 Kg6 66.Ke4 Bf8 67.Re5 Bd6 68.Rg5+ Kf6 69.Ra5 Bf8 70.Rh5 Kg6 71.Rg5+ Kf6
+- (2.32) Depth: 58/95 01:33:56 186151MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bf6 62.Rb8 Bh4 63.Ke3 Be7 64.Rc8 Bf6 65.Ke4 Kg6 66.Rc6 Kg7 67.Kf5 Bh4 68.Rc3 h6 69.Rh3 Bf2 70.Rd3
+- (2.32) Depth: 59/92 01:43:30 206243MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bf6 62.Rb8 Bc3 63.Kd3 Bf6 64.Ra8 Kg6 65.Ke4 Kg7 66.Ra6 Be7 67.Kf5 Bc5 68.Rc6 Bd4 69.Ra6 Bg1 70.Rc6
+- (2.32) Depth: 60/93 01:45:02 209430MN
24.Rxd5
+- (2.40 ++) Depth: 61/95 02:30:58 303147MN
24.Rxd5
+- (2.47 ++) Depth: 61/95 03:05:39 374238MN
24.Rxd5
+- (2.59 ++) Depth: 61/95 03:33:24 430869MN
24.Rxd5
+- (2.75 ++) Depth: 61/95 04:50:53 589776MN
24.Rxd5 exd5 25.Rd1 Qg8 26.Bxd5 Rxd5 27.Rxd5 c4 28.Rd4 Qg6 29.Qf3 Re8 30.bxc4 bxc4 31.Rxc4 Qg5 32.Bc3 Bxc3 33.Qxc3 h6 34.h4 Qe5 35.Qf3 Qe6 36.Rc6 Qh3 37.Rc1 Qe6 38.Rc7 Kh7 39.Kh2 a4 40.Ra7 a3 41.Rxa3 Qe4 42.Qxe4+ Rxe4 43.h5 Re6 44.Rf3 Re5 45.g4 Re2 46.Kg3 Rd2 47.Rf5 Rd3+ 48.Kg2 Rd2 49.Kf3 Ra2 50.Rd5 Kg8 51.Rb5 Ra6 52.Rf5 Ra2 53.Re5 Kf8 54.Rb5 Kg8 55.Rb8+ Kh7 56.Rb7 Kg8 57.Rb6 Ra3+ 58.Kg2 Ra2 59.Rb8+ Kh7 60.Rb7 Kg8 61.Rb6 Kh8
+- (2.75) Depth: 61/95 05:03:32 615812MN
24.Rxd5
+- (2.82 ++) Depth: 62/96 06:39:43 814089MN
24.Rxd5
+- (2.90 ++) Depth: 62/96 06:51:33 838857MN

[acase]

sorry Eelco,

I am doing many things at the same time/analysing many positions simultaneously, so probably I am doing everything wrong,
but where is white win after d4.

[d]r2r1q1k/5p1p/5P2/ppp1B2Q/1b1p4/1P4P1/5PBP/3R2K1 w - - 0 3

my SF does not see it.

Hi Lyudmil,


I set up the position after 25...d4 and let Stockfish analyze it a little bit, and Stockfish on my computer seems to think black is without any doubt toast after 25...d4 by playing 26.Be4!:


New game
r2r1q1k/5p1p/5P2/ppp1B2Q/1b1p4/1P4P1/5PBP/3R2K1 w - - 0 1

Analysis by Stockfish 190817 64 BMI2:


26.g4 Qg8 27.Be4 Re8 28.Rd3 c4 29.Rh3 Rxe5 30.Qxe5 Re8 31.Qf5 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bxh2 41.Rf5 Qg6 42.Qxd4 c2 43.Qc4 Bd6 44.f3 h5 45.Rxh5 Bf8 46.Rh2 Qf6 47.Rxc2 Qxf3+ 48.Rf2 Qd1+ 49.Kg2 Qd7 50.Rf5 Qd2+ 51.Kf3 Qd1+ 52.Kf2 Qd2+ 53.Qe2 Qd8 54.Qe3 Be7 55.Qe4 Qd2+ 56.Kf1 Qd6 57.Kg2 Kg7 58.Rd5 Qf6 59.Qd4 Qxd4 60.Rxd4 Kf6 61.Kf3 Ke6 62.Ra4 Kd5 63.Ra7
+- (3.60) Depth: 44/99 00:04:06 8685MN
26.g4
+- (3.67 ++) Depth: 45/91 00:04:46 10113MN
26.g4 Qg8
+- (3.52 --) Depth: 45/91 00:05:01 10633MN
26.g4 Qg8
+- (3.41 --) Depth: 45/91 00:05:01 10649MN
26.g4 Qg8
+- (3.25 --) Depth: 45/91 00:05:02 10674MN
26.g4
+- (3.39 ++) Depth: 45/91 00:05:05 10791MN
26.g4
+- (3.68 ++) Depth: 45/91 00:05:16 11184MN
26.g4 Qg8
+- (3.04 --) Depth: 45/91 00:05:34 11814MN
26.Be4
+- (3.55 ++) Depth: 45/91 00:05:40 12005MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Bf8 37.f3 Qg6 38.Qxb5 Qxf6 39.Qd3 h6 40.Rf5 Qc6 41.Qxd4+ Kg8 42.Rf4 Qc7 43.Qc4 Qe7 44.Rf5 Qe6 45.Qxc3 Qe2+ 46.Kg3 Bb4 47.Qc4 Bd6+ 48.f4 Qe1+ 49.Kg2 Qd2+ 50.Kf3 Qd1+ 51.Kf2 Qd2+ 52.Qe2 Bxf4 53.Qxd2 Bxd2 54.Kf3 Kg7 55.Ke4 Be1 56.Rf1 Bb4 57.Kf5 Bd6 58.h4 Be7 59.h5 Kh7 60.Ra1 Bb4
+- (3.73) Depth: 45/91 00:05:56 12569MN
26.Be4 Qg8
+- (3.65 --) Depth: 46/90 00:06:01 12762MN
26.Be4 Qg8
+- (3.58 --) Depth: 46/90 00:06:02 12777MN
26.Be4
+- (3.65 ++) Depth: 46/90 00:06:04 12883MN
26.Be4 Qg8
+- (3.47 --) Depth: 46/95 00:06:39 14086MN
26.Be4
+- (3.64 ++) Depth: 46/95 00:06:46 14334MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 c4 29.Rh3 Rxe5 30.Qxe5 Re8 31.Qf4 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Qd6 42.Ke2 Bg7 43.Rc4 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Kxd4 Qxb4+ 49.Ke3 c2 50.Ke2 Qe7+ 51.Kf1 Qg5 52.Qxg5+ hxg5 53.Rxc2 Bd6 54.Kg2 Kf8 55.h3 Ke7 56.Kf3 Kd7 57.Ke4 f6 58.Kf5 Be5 59.Rc4 Kd6 60.Ra4 Kd5 61.Ra5+ Kc4
+- (3.69) Depth: 46/95 00:07:24 15694MN
26.Be4
+- (3.77 ++) Depth: 47/80 00:07:43 16355MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Qd6 42.Ke2 Bg7 43.Rc4 h6 44.Kd3 Qa6 45.Qf5 Bf8 46.Kxd4 Qa2 47.Ke3 Qxb3 48.Qd3 Qb8 49.h3 Bg7 50.Qd7 Qb6+ 51.Kf3 Qf6+ 52.Ke2 Qe5+ 53.Kf1 Qe6 54.Rc8+ Kh7 55.Qd3+ Qg6 56.Ke2 Qxd3+ 57.Kxd3 h5 58.gxh5 Kh6 59.Rc7 Kxh5 60.Rxf7 Kg6 61.Rc7 Be5 62.Rc5 Kf5 63.h4 c2 64.Rxc2
+- (3.77) Depth: 47/101 00:08:14 17433MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Bg7 42.Rc4 Qd6 43.Ke2 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Qc5 Qd1+ 49.Kc4 Qe2+ 50.Kxd4 Qxf2+ 51.Kxc3 Qf3+ 52.Kd2 Qf4+ 53.Kc2 Qe4+ 54.Kb3 Qd3+ 55.Qc3 Qe2 56.h3 Qd1+ 57.Ka3 Qd6 58.Ra8 Qd1 59.Kb2 Qe2+ 60.Kb3 Qe6+ 61.Ka3 Qe2 62.Rd8 Qa6+ 63.Kb3 Qe6+ 64.Qc4 Qe7 65.Rc8 Qe3+ 66.Kc2 Qf2+ 67.Kc3 Qe3+ 68.Kb2 Qf2+ 69.Qc2 Qe3 70.Qc5 Qd2+ 71.Ka3 Qd3+ 72.Ka4
+- (3.84) Depth: 48/97 00:09:42 20505MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Bg7 42.Rc4 Qd6 43.Ke2 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Qc5 Qd1+ 49.Kc4 Qe2+ 50.Kxd4 Qxf2+ 51.Kxc3 Qf3+ 52.Kd2 Qf4+ 53.Kc2 Qe4+ 54.Kb3 Qd3+ 55.Qc3 Qe2 56.h3 Qd1+ 57.Ka3 Qd6 58.Ra8 Qd1 59.Kb2 Qe2+ 60.Kb3 Qe6+ 61.Ka3 Qe2 62.Rd8 Qa6+ 63.Kb3 Qe6+ 64.Qc4 Qe7 65.Qd4 Qe6+ 66.Kc3 Qe1+ 67.Qd2 Qe5+ 68.Kb3 Qe6+ 69.Qd5 Qe7
+- (3.84) Depth: 49/88 00:09:58 21080MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Bg7 42.Rc4 Qd6 43.Ke2 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Qc5 Qd1+ 49.Kc4 Qe2+ 50.Kxd4 Qxf2+ 51.Kxc3 Qf3+ 52.Kd2 Qf4+ 53.Kc2 Qe4+ 54.Kb3 Qd3+ 55.Qc3 Qe2 56.h3 Qd1+ 57.Ka3 Qd6 58.Ra8 Qd1 59.Kb2 Qe2+ 60.Kb3 Qe6+ 61.Ka3 Qe2 62.Rd8 Qa6+ 63.Kb3 Qe6+ 64.Qc4 Qe7 65.Qd4 Qe6+ 66.Kc3 Qe1+ 67.Kc2 Qe2+ 68.Qd2 Qe6 69.Qc3 Qe7
+- (3.84) Depth: 50/90 00:10:18 21775MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Bg7 42.Rc4 Qd6 43.Ke2 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Qc5 Qd1+ 49.Kc4 Qe2+ 50.Kxd4 Qxf2+ 51.Kxc3 Qf3+ 52.Kd2 Qf4+ 53.Kc2 Qe4+ 54.Kb3 Qd3+ 55.Qc3 Qe2 56.h3 Qe6+ 57.Kb2 Qe2+ 58.Qc2 Qe5+ 59.Ka2 Kg7 60.Kb3 Qd5+ 61.Ka4 Qb7 62.Qc3+ Kg8 63.Kb3 Qd5+ 64.Ka3 Qd6 65.Ra8 Qd1 66.Kb2 Qe2+ 67.Kb3 Qe6+ 68.Ka3 Qe2 69.Rb8 Qa6+ 70.Kb3 Qe6+ 71.Kc2 Qe7 72.Qc8 Kg7 73.Kb3 Qd6 74.Qc3+ Kg8 75.Re8 Qd1+ 76.Kb2
+- (3.84) Depth: 51/105 00:11:26 24151MN
26.Be4 Qg8
+- (3.76 --) Depth: 52/105 00:11:51 25032MN
26.Be4
+- (3.84 ++) Depth: 52/105 00:12:28 26290MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 c4 29.Rh3 Rxe5 30.Qxe5 Re8 31.Qf5 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Bg7 42.Rc4 Qd6 43.Ke2 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Qc5 Qd1+ 49.Kc4 Qe2+ 50.Kd5 Qf3+ 51.Kxd4 Qxf2+ 52.Kxc3 Qf3+ 53.Kd2 Qf4+ 54.Kc2 Qe4+ 55.Kb3 Qd3+ 56.Qc3 Qd5+ 57.Ka3 Qb7 58.h3 Qa6+ 59.Kb2 Qd6 60.Kb3 Qd7 61.Kc2 Qd5 62.Re8 Qg2+ 63.Kb3 Qd5+ 64.Ka3 Qa5+ 65.Kb2 Qd5 66.Rb8 Qd6 67.Rc8 Qe6 68.Qc4 Qe5+ 69.Kc2
+- (3.84) Depth: 52/105 00:13:28 28362MN

[Eelco de Groot]

ok, it sees high scores after white's g4, followed by Rd3 to swing to h3, have to feed it manually to SF, seems to be too deep for it, but is it won?

in one of the lines I get here:

[d]8/3R1pkp/5b2/5K2/5P2/8/7P/8 w - - 0 29

anyone with 8-men?

ok, here is the fully forced line: Rd5!!(??) ed5 Rd1 d4 Be4 Qg8 g4 Re8 Rd3 c4 Rh3 Re5 Qe5 Re8 Qf4 Re4 Qe4 c3:

[d]6qk/5p1p/5P2/pp6/1b1pQ1P1/1Pp4R/5P1P/6K1 w - - 0 10

is this necessarily won for white?

I get to mostly some possible fortresses.

Okay, I concur this looks like a fortress and the evaluation is much too high. Well seen Lyudmil! Apologies that I went too quickly over this line.

[pgn]
[Event "?"]
[Site "?"]
[Date "2017.08.20"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "r2r1q1k/5p1p/4pP2/pppbB2Q/1b6/1P4P1/5PBP/R2R2K1 w - -"]

1. Rxd5 exd5 2. Rd1 d4 3. Be4 Qg8 4. g4 Re8 5. Rd3 c4
6. Rh3 Rxe5 7. Qxe5 Re8 8. Qf4 Rxe4 9. Qxe4 c3 10. Kh1 Qg6
11. Qe8+ Qg8 12. Qc6 Qg6 13. Rd3 h6 14. Rxd4 Kh7 15. f3
Qb1+ 16. Kg2 Qc2+ 17. Kg3 Qe2 18. Rd7 Kg6 19. Rd8 Kh7 *
[/pgn]

[Eelco de Groot]

Thanks Andrew, this does not seem very difficult for almost default Stockfish development version

Hello Eelco,

Thanks for your fast reply.
What do you mean by "almost default Stockfish development version"?

Do you mean that you modified the code slightly? or do you mean you changed the default engine settings?


My Stockfish DV 8/19/2017 with default settings finally gets this one after a little more than 27 minutes:


24.Bc7 Rd7 25.Be4 Qg8 26.Bxd5 exd5 27.Rxd5 Rxd5 28.Qxd5 a4 29.bxa4 bxa4 30.Bd6 Bc3 31.Ra2 Bxf6 32.Be5 Kg7 33.Bxf6+ Kxf6 34.Qxc5 Qc8 35.Qxc8 Rxc8 36.Rxa4 h5 37.Kg2 Rc3 38.Ra6+ Kf5 39.Ra5+ Kg6 40.Rd5 Rb3 41.h4 Kh6 42.Rf5 Kg6 43.Rg5+ Kh6 44.Rd5 Kg6 45.Kg1 Rb1+ 46.Kh2 f6 47.Kg2 Rb3 48.Rd2 Rb5 49.f3 Kf5 50.Rc2 Kg6 51.Kf2 Kf5 52.Ke3 Rb3+ 53.Ke2 Rb5
+/- (0.80) Depth: 49/72 00:20:57 40336MN
24.Rxd5
+/- (0.87 ++) Depth: 50/67 00:27:17 52764MN
24.Rxd5
+/- (0.95 ++) Depth: 50/67 00:29:43 57483MN
24.Rxd5
+/- (1.06 ++) Depth: 50/67 00:31:49 61560MN
24.Rxd5
+/- (1.22 ++) Depth: 50/67 00:34:11 66196MN
24.Rxd5
+/- (1.44 ++) Depth: 50/67 00:37:20 72317MN
24.Rxd5
+- (1.73 ++) Depth: 50/67 00:42:07 81621MN
24.Rxd5
+- (2.11 ++) Depth: 50/82 00:54:04 105335MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rd7 Ba5 63.Rd6+ Kg7 64.Kf5 Be1
+- (2.32) Depth: 50/91 01:10:13 137959MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rb4 Bf6 63.Rb6 Kg7 64.Kd5 Bd8
+- (2.32) Depth: 51/82 01:11:21 140229MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rb5 Bf6 63.Rb6 Kg7 64.Ra6 h5 65.Rd6 Bc3 66.Kf5 h4
+- (2.32) Depth: 52/86 01:12:51 143280MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rb5 Bf6 63.Rb6 Kg7 64.Ra6 Kg6 65.Rc6 Kg7 66.Rc8 Be7 67.Ke3 Kf6
+- (2.32) Depth: 53/88 01:14:03 145744MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf5 Ba3 64.Rc7 Bb2 65.Kg5 Bf6+ 66.Kg4 Kf8 67.Kf3 Bg7 68.Rb7
+- (2.32) Depth: 54/90 01:16:04 149818MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf5 h6 64.Rd7 Bb4 65.Rd3 Be1 66.Rb3 Bd2 67.Ke4 Kf6 68.Rb5
+- (2.32) Depth: 55/103 01:18:18 154333MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf5 h6 64.Rb6 Bc5 65.Rb3 Bd4 66.Rd3 Bc5 67.Ke5 Bf2 68.Kf5 Be1 69.Rb3
+- (2.32) Depth: 56/91 01:24:06 166203MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf3 Bc5 64.Rd7 Bg1 65.Ke4 Kf8 66.Rd8+ Kg7 67.Rb8 Kf6 68.Rg8 Bb6 69.Rb8 Bc7
+- (2.32) Depth: 57/92 01:27:16 172572MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rg5+ Kf6 63.Rf5+ Kg7 64.Kd3 Bd6 65.Ke3 Kg6 66.Ke4 Bf8 67.Re5 Bd6 68.Rg5+ Kf6 69.Ra5 Bf8 70.Rh5 Kg6 71.Rg5+ Kf6
+- (2.32) Depth: 58/95 01:33:56 186151MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bf6 62.Rb8 Bh4 63.Ke3 Be7 64.Rc8 Bf6 65.Ke4 Kg6 66.Rc6 Kg7 67.Kf5 Bh4 68.Rc3 h6 69.Rh3 Bf2 70.Rd3
+- (2.32) Depth: 59/92 01:43:30 206243MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bf6 62.Rb8 Bc3 63.Kd3 Bf6 64.Ra8 Kg6 65.Ke4 Kg7 66.Ra6 Be7 67.Kf5 Bc5 68.Rc6 Bd4 69.Ra6 Bg1 70.Rc6
+- (2.32) Depth: 60/93 01:45:02 209430MN
24.Rxd5
+- (2.40 ++) Depth: 61/95 02:30:58 303147MN
24.Rxd5
+- (2.47 ++) Depth: 61/95 03:05:39 374238MN
24.Rxd5
+- (2.59 ++) Depth: 61/95 03:33:24 430869MN
24.Rxd5
+- (2.75 ++) Depth: 61/95 04:50:53 589776MN
24.Rxd5 exd5 25.Rd1 Qg8 26.Bxd5 Rxd5 27.Rxd5 c4 28.Rd4 Qg6 29.Qf3 Re8 30.bxc4 bxc4 31.Rxc4 Qg5 32.Bc3 Bxc3 33.Qxc3 h6 34.h4 Qe5 35.Qf3 Qe6 36.Rc6 Qh3 37.Rc1 Qe6 38.Rc7 Kh7 39.Kh2 a4 40.Ra7 a3 41.Rxa3 Qe4 42.Qxe4+ Rxe4 43.h5 Re6 44.Rf3 Re5 45.g4 Re2 46.Kg3 Rd2 47.Rf5 Rd3+ 48.Kg2 Rd2 49.Kf3 Ra2 50.Rd5 Kg8 51.Rb5 Ra6 52.Rf5 Ra2 53.Re5 Kf8 54.Rb5 Kg8 55.Rb8+ Kh7 56.Rb7 Kg8 57.Rb6 Ra3+ 58.Kg2 Ra2 59.Rb8+ Kh7 60.Rb7 Kg8 61.Rb6 Kh8
+- (2.75) Depth: 61/95 05:03:32 615812MN
24.Rxd5
+- (2.82 ++) Depth: 62/96 06:39:43 814089MN
24.Rxd5
+- (2.90 ++) Depth: 62/96 06:51:33 838857MN

Hi Andrew, I changed the code slightly and may have uncovered an inconsistency that could be helpful if changed. But I also changed a bit code with passed pawn evaluation and although I don't see many passed pawns here, it might also influence the differences seen. But my guess is that is not the real change. But the search change alone could still be a loss overall.

It is a very small change in my eyes. Not much more than placing a flag in a different place and because you do less special casing it would only have to pass [-3, 1] SPRT parameters. Qualifies definitely as a simplification, even if you need a few extra lines. -For me it adds one line but it could be prettier with some rewriting. But that is not so important. I have no idea about actual Elo impact yet.

But I think Lyudmil is right after all: Stockfish' 3.84 evaluation is not to be trusted!! A bit of a pity for your testposition Andrew, but good on Lyudmil.

[Lyudmil Tsvetkov]

Thanks Andrew, this does not seem very difficult for almost default Stockfish development version

Hello Eelco,

Thanks for your fast reply.
What do you mean by "almost default Stockfish development version"?

Do you mean that you modified the code slightly? or do you mean you changed the default engine settings?


My Stockfish DV 8/19/2017 with default settings finally gets this one after a little more than 27 minutes:


24.Bc7 Rd7 25.Be4 Qg8 26.Bxd5 exd5 27.Rxd5 Rxd5 28.Qxd5 a4 29.bxa4 bxa4 30.Bd6 Bc3 31.Ra2 Bxf6 32.Be5 Kg7 33.Bxf6+ Kxf6 34.Qxc5 Qc8 35.Qxc8 Rxc8 36.Rxa4 h5 37.Kg2 Rc3 38.Ra6+ Kf5 39.Ra5+ Kg6 40.Rd5 Rb3 41.h4 Kh6 42.Rf5 Kg6 43.Rg5+ Kh6 44.Rd5 Kg6 45.Kg1 Rb1+ 46.Kh2 f6 47.Kg2 Rb3 48.Rd2 Rb5 49.f3 Kf5 50.Rc2 Kg6 51.Kf2 Kf5 52.Ke3 Rb3+ 53.Ke2 Rb5
+/- (0.80) Depth: 49/72 00:20:57 40336MN
24.Rxd5
+/- (0.87 ++) Depth: 50/67 00:27:17 52764MN
24.Rxd5
+/- (0.95 ++) Depth: 50/67 00:29:43 57483MN
24.Rxd5
+/- (1.06 ++) Depth: 50/67 00:31:49 61560MN
24.Rxd5
+/- (1.22 ++) Depth: 50/67 00:34:11 66196MN
24.Rxd5
+/- (1.44 ++) Depth: 50/67 00:37:20 72317MN
24.Rxd5
+- (1.73 ++) Depth: 50/67 00:42:07 81621MN
24.Rxd5
+- (2.11 ++) Depth: 50/82 00:54:04 105335MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rd7 Ba5 63.Rd6+ Kg7 64.Kf5 Be1
+- (2.32) Depth: 50/91 01:10:13 137959MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rb4 Bf6 63.Rb6 Kg7 64.Kd5 Bd8
+- (2.32) Depth: 51/82 01:11:21 140229MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rb5 Bf6 63.Rb6 Kg7 64.Ra6 h5 65.Rd6 Bc3 66.Kf5 h4
+- (2.32) Depth: 52/86 01:12:51 143280MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb7 Kg6 62.Rb5 Bf6 63.Rb6 Kg7 64.Ra6 Kg6 65.Rc6 Kg7 66.Rc8 Be7 67.Ke3 Kf6
+- (2.32) Depth: 53/88 01:14:03 145744MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rd2 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf5 Ba3 64.Rc7 Bb2 65.Kg5 Bf6+ 66.Kg4 Kf8 67.Kf3 Bg7 68.Rb7
+- (2.32) Depth: 54/90 01:16:04 149818MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf5 h6 64.Rd7 Bb4 65.Rd3 Be1 66.Rb3 Bd2 67.Ke4 Kf6 68.Rb5
+- (2.32) Depth: 55/103 01:18:18 154333MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf5 h6 64.Rb6 Bc5 65.Rb3 Bd4 66.Rd3 Bc5 67.Ke5 Bf2 68.Kf5 Be1 69.Rb3
+- (2.32) Depth: 56/91 01:24:06 166203MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rb7 Bd6 63.Kf3 Bc5 64.Rd7 Bg1 65.Ke4 Kf8 66.Rd8+ Kg7 67.Rb8 Kf6 68.Rg8 Bb6 69.Rb8 Bc7
+- (2.32) Depth: 57/92 01:27:16 172572MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bc7 62.Rg5+ Kf6 63.Rf5+ Kg7 64.Kd3 Bd6 65.Ke3 Kg6 66.Ke4 Bf8 67.Re5 Bd6 68.Rg5+ Kf6 69.Ra5 Bf8 70.Rh5 Kg6 71.Rg5+ Kf6
+- (2.32) Depth: 58/95 01:33:56 186151MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bf6 62.Rb8 Bh4 63.Ke3 Be7 64.Rc8 Bf6 65.Ke4 Kg6 66.Rc6 Kg7 67.Kf5 Bh4 68.Rc3 h6 69.Rh3 Bf2 70.Rd3
+- (2.32) Depth: 59/92 01:43:30 206243MN
24.Rxd5 exd5 25.Rd1 d4 26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Rh5 a4 34.Rxb5 c2 35.Qxc2 Qxg4+ 36.Kf1 Qh3+ 37.Ke2 Qg4+ 38.f3 Qg2+ 39.Kd3 Qg6+ 40.Kxd4 Qxf6+ 41.Ke3 Qh6+ 42.f4 Qh3+ 43.Kd4 Qd7+ 44.Rd5 axb3 45.Qxb3 Qa7+ 46.Ke4 Be7 47.Rf5 Qa8+ 48.Qd5 Qxd5+ 49.Rxd5 Kg7 50.Kf5 Bf6 51.Rd7 Bc3 52.Rd6 Bb4 53.Rd3 Be1 54.Rd5 Bh4 55.Rd7 Kf8 56.Ke5 Kg7 57.Rb7 Kg6 58.Rb3 Bf6+ 59.Ke4 Kg7 60.Rb6 Bd8 61.Rb5 Bf6 62.Rb8 Bc3 63.Kd3 Bf6 64.Ra8 Kg6 65.Ke4 Kg7 66.Ra6 Be7 67.Kf5 Bc5 68.Rc6 Bd4 69.Ra6 Bg1 70.Rc6
+- (2.32) Depth: 60/93 01:45:02 209430MN
24.Rxd5
+- (2.40 ++) Depth: 61/95 02:30:58 303147MN
24.Rxd5
+- (2.47 ++) Depth: 61/95 03:05:39 374238MN
24.Rxd5
+- (2.59 ++) Depth: 61/95 03:33:24 430869MN
24.Rxd5
+- (2.75 ++) Depth: 61/95 04:50:53 589776MN
24.Rxd5 exd5 25.Rd1 Qg8 26.Bxd5 Rxd5 27.Rxd5 c4 28.Rd4 Qg6 29.Qf3 Re8 30.bxc4 bxc4 31.Rxc4 Qg5 32.Bc3 Bxc3 33.Qxc3 h6 34.h4 Qe5 35.Qf3 Qe6 36.Rc6 Qh3 37.Rc1 Qe6 38.Rc7 Kh7 39.Kh2 a4 40.Ra7 a3 41.Rxa3 Qe4 42.Qxe4+ Rxe4 43.h5 Re6 44.Rf3 Re5 45.g4 Re2 46.Kg3 Rd2 47.Rf5 Rd3+ 48.Kg2 Rd2 49.Kf3 Ra2 50.Rd5 Kg8 51.Rb5 Ra6 52.Rf5 Ra2 53.Re5 Kf8 54.Rb5 Kg8 55.Rb8+ Kh7 56.Rb7 Kg8 57.Rb6 Ra3+ 58.Kg2 Ra2 59.Rb8+ Kh7 60.Rb7 Kg8 61.Rb6 Kh8
+- (2.75) Depth: 61/95 05:03:32 615812MN
24.Rxd5
+- (2.82 ++) Depth: 62/96 06:39:43 814089MN
24.Rxd5
+- (2.90 ++) Depth: 62/96 06:51:33 838857MN

the Rd1 d4 line seems inconclusive: SF still at 232 cps after a very long search.

Rd1 Qg8 seems easily won for white.

[Lyudmil Tsvetkov]

sorry Eelco,

I am doing many things at the same time/analysing many positions simultaneously, so probably I am doing everything wrong,
but where is white win after d4.

[d]r2r1q1k/5p1p/5P2/ppp1B2Q/1b1p4/1P4P1/5PBP/3R2K1 w - - 0 3

my SF does not see it.

Hi Lyudmil,


I set up the position after 25...d4 and let Stockfish analyze it a little bit, and Stockfish on my computer seems to think black is without any doubt toast after 25...d4 by playing 26.Be4!:


New game
r2r1q1k/5p1p/5P2/ppp1B2Q/1b1p4/1P4P1/5PBP/3R2K1 w - - 0 1

Analysis by Stockfish 190817 64 BMI2:


26.g4 Qg8 27.Be4 Re8 28.Rd3 c4 29.Rh3 Rxe5 30.Qxe5 Re8 31.Qf5 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bxh2 41.Rf5 Qg6 42.Qxd4 c2 43.Qc4 Bd6 44.f3 h5 45.Rxh5 Bf8 46.Rh2 Qf6 47.Rxc2 Qxf3+ 48.Rf2 Qd1+ 49.Kg2 Qd7 50.Rf5 Qd2+ 51.Kf3 Qd1+ 52.Kf2 Qd2+ 53.Qe2 Qd8 54.Qe3 Be7 55.Qe4 Qd2+ 56.Kf1 Qd6 57.Kg2 Kg7 58.Rd5 Qf6 59.Qd4 Qxd4 60.Rxd4 Kf6 61.Kf3 Ke6 62.Ra4 Kd5 63.Ra7
+- (3.60) Depth: 44/99 00:04:06 8685MN
26.g4
+- (3.67 ++) Depth: 45/91 00:04:46 10113MN
26.g4 Qg8
+- (3.52 --) Depth: 45/91 00:05:01 10633MN
26.g4 Qg8
+- (3.41 --) Depth: 45/91 00:05:01 10649MN
26.g4 Qg8
+- (3.25 --) Depth: 45/91 00:05:02 10674MN
26.g4
+- (3.39 ++) Depth: 45/91 00:05:05 10791MN
26.g4
+- (3.68 ++) Depth: 45/91 00:05:16 11184MN
26.g4 Qg8
+- (3.04 --) Depth: 45/91 00:05:34 11814MN
26.Be4
+- (3.55 ++) Depth: 45/91 00:05:40 12005MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Bf8 37.f3 Qg6 38.Qxb5 Qxf6 39.Qd3 h6 40.Rf5 Qc6 41.Qxd4+ Kg8 42.Rf4 Qc7 43.Qc4 Qe7 44.Rf5 Qe6 45.Qxc3 Qe2+ 46.Kg3 Bb4 47.Qc4 Bd6+ 48.f4 Qe1+ 49.Kg2 Qd2+ 50.Kf3 Qd1+ 51.Kf2 Qd2+ 52.Qe2 Bxf4 53.Qxd2 Bxd2 54.Kf3 Kg7 55.Ke4 Be1 56.Rf1 Bb4 57.Kf5 Bd6 58.h4 Be7 59.h5 Kh7 60.Ra1 Bb4
+- (3.73) Depth: 45/91 00:05:56 12569MN
26.Be4 Qg8
+- (3.65 --) Depth: 46/90 00:06:01 12762MN
26.Be4 Qg8
+- (3.58 --) Depth: 46/90 00:06:02 12777MN
26.Be4
+- (3.65 ++) Depth: 46/90 00:06:04 12883MN
26.Be4 Qg8
+- (3.47 --) Depth: 46/95 00:06:39 14086MN
26.Be4
+- (3.64 ++) Depth: 46/95 00:06:46 14334MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 c4 29.Rh3 Rxe5 30.Qxe5 Re8 31.Qf4 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Qd6 42.Ke2 Bg7 43.Rc4 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Kxd4 Qxb4+ 49.Ke3 c2 50.Ke2 Qe7+ 51.Kf1 Qg5 52.Qxg5+ hxg5 53.Rxc2 Bd6 54.Kg2 Kf8 55.h3 Ke7 56.Kf3 Kd7 57.Ke4 f6 58.Kf5 Be5 59.Rc4 Kd6 60.Ra4 Kd5 61.Ra5+ Kc4
+- (3.69) Depth: 46/95 00:07:24 15694MN
26.Be4
+- (3.77 ++) Depth: 47/80 00:07:43 16355MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Qd6 42.Ke2 Bg7 43.Rc4 h6 44.Kd3 Qa6 45.Qf5 Bf8 46.Kxd4 Qa2 47.Ke3 Qxb3 48.Qd3 Qb8 49.h3 Bg7 50.Qd7 Qb6+ 51.Kf3 Qf6+ 52.Ke2 Qe5+ 53.Kf1 Qe6 54.Rc8+ Kh7 55.Qd3+ Qg6 56.Ke2 Qxd3+ 57.Kxd3 h5 58.gxh5 Kh6 59.Rc7 Kxh5 60.Rxf7 Kg6 61.Rc7 Be5 62.Rc5 Kf5 63.h4 c2 64.Rxc2
+- (3.77) Depth: 47/101 00:08:14 17433MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Bg7 42.Rc4 Qd6 43.Ke2 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Qc5 Qd1+ 49.Kc4 Qe2+ 50.Kxd4 Qxf2+ 51.Kxc3 Qf3+ 52.Kd2 Qf4+ 53.Kc2 Qe4+ 54.Kb3 Qd3+ 55.Qc3 Qe2 56.h3 Qd1+ 57.Ka3 Qd6 58.Ra8 Qd1 59.Kb2 Qe2+ 60.Kb3 Qe6+ 61.Ka3 Qe2 62.Rd8 Qa6+ 63.Kb3 Qe6+ 64.Qc4 Qe7 65.Rc8 Qe3+ 66.Kc2 Qf2+ 67.Kc3 Qe3+ 68.Kb2 Qf2+ 69.Qc2 Qe3 70.Qc5 Qd2+ 71.Ka3 Qd3+ 72.Ka4
+- (3.84) Depth: 48/97 00:09:42 20505MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Bg7 42.Rc4 Qd6 43.Ke2 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Qc5 Qd1+ 49.Kc4 Qe2+ 50.Kxd4 Qxf2+ 51.Kxc3 Qf3+ 52.Kd2 Qf4+ 53.Kc2 Qe4+ 54.Kb3 Qd3+ 55.Qc3 Qe2 56.h3 Qd1+ 57.Ka3 Qd6 58.Ra8 Qd1 59.Kb2 Qe2+ 60.Kb3 Qe6+ 61.Ka3 Qe2 62.Rd8 Qa6+ 63.Kb3 Qe6+ 64.Qc4 Qe7 65.Qd4 Qe6+ 66.Kc3 Qe1+ 67.Qd2 Qe5+ 68.Kb3 Qe6+ 69.Qd5 Qe7
+- (3.84) Depth: 49/88 00:09:58 21080MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Bg7 42.Rc4 Qd6 43.Ke2 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Qc5 Qd1+ 49.Kc4 Qe2+ 50.Kxd4 Qxf2+ 51.Kxc3 Qf3+ 52.Kd2 Qf4+ 53.Kc2 Qe4+ 54.Kb3 Qd3+ 55.Qc3 Qe2 56.h3 Qd1+ 57.Ka3 Qd6 58.Ra8 Qd1 59.Kb2 Qe2+ 60.Kb3 Qe6+ 61.Ka3 Qe2 62.Rd8 Qa6+ 63.Kb3 Qe6+ 64.Qc4 Qe7 65.Qd4 Qe6+ 66.Kc3 Qe1+ 67.Kc2 Qe2+ 68.Qd2 Qe6 69.Qc3 Qe7
+- (3.84) Depth: 50/90 00:10:18 21775MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 Rxe5 29.Qxe5 Re8 30.Qf4 c4 31.Rh3 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Bg7 42.Rc4 Qd6 43.Ke2 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Qc5 Qd1+ 49.Kc4 Qe2+ 50.Kxd4 Qxf2+ 51.Kxc3 Qf3+ 52.Kd2 Qf4+ 53.Kc2 Qe4+ 54.Kb3 Qd3+ 55.Qc3 Qe2 56.h3 Qe6+ 57.Kb2 Qe2+ 58.Qc2 Qe5+ 59.Ka2 Kg7 60.Kb3 Qd5+ 61.Ka4 Qb7 62.Qc3+ Kg8 63.Kb3 Qd5+ 64.Ka3 Qd6 65.Ra8 Qd1 66.Kb2 Qe2+ 67.Kb3 Qe6+ 68.Ka3 Qe2 69.Rb8 Qa6+ 70.Kb3 Qe6+ 71.Kc2 Qe7 72.Qc8 Kg7 73.Kb3 Qd6 74.Qc3+ Kg8 75.Re8 Qd1+ 76.Kb2
+- (3.84) Depth: 51/105 00:11:26 24151MN
26.Be4 Qg8
+- (3.76 --) Depth: 52/105 00:11:51 25032MN
26.Be4
+- (3.84 ++) Depth: 52/105 00:12:28 26290MN
26.Be4 Qg8 27.g4 Re8 28.Rd3 c4 29.Rh3 Rxe5 30.Qxe5 Re8 31.Qf5 Rxe4 32.Qxe4 c3 33.Kg2 Ba3 34.Rh5 Qg6 35.Qe8+ Qg8 36.Qe2 Qg6 37.Rxb5 Qxf6 38.Qe4 Kg8 39.Rxa5 Bd6 40.Kf1 Bf8 41.Ra4 Bg7 42.Rc4 Qd6 43.Ke2 h6 44.Kd3 Qb8 45.b4 Qb5 46.Qf5 Qa4 47.Rc8+ Bf8 48.Qc5 Qd1+ 49.Kc4 Qe2+ 50.Kd5 Qf3+ 51.Kxd4 Qxf2+ 52.Kxc3 Qf3+ 53.Kd2 Qf4+ 54.Kc2 Qe4+ 55.Kb3 Qd3+ 56.Qc3 Qd5+ 57.Ka3 Qb7 58.h3 Qa6+ 59.Kb2 Qd6 60.Kb3 Qd7 61.Kc2 Qd5 62.Re8 Qg2+ 63.Kb3 Qd5+ 64.Ka3 Qa5+ 65.Kb2 Qd5 66.Rb8 Qd6 67.Rc8 Qe6 68.Qc4 Qe5+ 69.Kc2
+- (3.84) Depth: 52/105 00:13:28 28362MN

well, maybe, but for 10 plies score almost does not change, only some 20cps, so if not fully drawn, pretty close to being fortress.

33.Kg2 is an interesting try, pity I don't have the opportunity to test evrything every time, my point is that, although your position is great, you always post very well-thought positions, if white is able to win in some way, this would only in some 100 moves or so after a very long and tough struggle.

i.e., the start position is very close to being balanced, no forced obvious solution, my assessment is some 80cps or so white advantage, so maybe just winning, or very close to a draw, in both the Rd5 line and in my suggested Bf4.(in 10 moves the score for the Bf4 line should also rise to above 100cps, but maybe still a draw due to insufficient material)

I will check a bit more some of the lines when possible, you might be fully correct with your Rd5 decision, but I am still not certain(did not analyse it enough)

in any case, we should not be surprised SF does not easily find it, as it is very very deep.

[Lyudmil Tsvetkov]

ok, it sees high scores after white's g4, followed by Rd3 to swing to h3, have to feed it manually to SF, seems to be too deep for it, but is it won?

in one of the lines I get here:

[d]8/3R1pkp/5b2/5K2/5P2/8/7P/8 w - - 0 29

anyone with 8-men?

ok, here is the fully forced line: Rd5!!(??) ed5 Rd1 d4 Be4 Qg8 g4 Re8 Rd3 c4 Rh3 Re5 Qe5 Re8 Qf4 Re4 Qe4 c3:

[d]6qk/5p1p/5P2/pp6/1b1pQ1P1/1Pp4R/5P1P/6K1 w - - 0 10

is this necessarily won for white?

I get to mostly some possible fortresses.

Okay, I concur this looks like a fortress and the evaluation is much too high. Well seen Lyudmil! Apologies that I went too quickly over this line.

[pgn]
[Event "?"]
[Site "?"]
[Date "2017.08.20"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "r2r1q1k/5p1p/4pP2/pppbB2Q/1b6/1P4P1/5PBP/R2R2K1 w - -"]

1. Rxd5 exd5 2. Rd1 d4 3. Be4 Qg8 4. g4 Re8 5. Rd3 c4
6. Rh3 Rxe5 7. Qxe5 Re8 8. Qf4 Rxe4 9. Qxe4 c3 10. Kh1 Qg6
11. Qe8+ Qg8 12. Qc6 Qg6 13. Rd3 h6 14. Rxd4 Kh7 15. f3
Qb1+ 16. Kg2 Qc2+ 17. Kg3 Qe2 18. Rd7 Kg6 19. Rd8 Kh7 *
[/pgn]

nothing to apologise for, maybe I should be apologising.

I really don't know what it is, it certainly looks like a fortress, but maybe it is not after all.

simply not analysed enough.

Andrew posted a great position, my only point is that the start position is about equal, no forced solutions, so, if white wins, this will be some 100 moves into the game.

sometimes there are moves, no one of us has considered.

[Lyudmil Tsvetkov]

I don't see many passed pawns here

[d]6qk/5p1p/5P2/pp6/1b1pQ1P1/1Pp4R/5P1P/6K1 w - - 0 8

c3, d4, a4(soon)

[Nordlandia]

Winning according SF Dev.

[d]8/3R1pkp/5b2/5K2/5P2/8/7P/8 w - - 0 29

[Nordlandia]

Is this winning for white?

Queen is trapped.

Code: Select all

1. e4 c6 2. d4 d5 3. e5 Bf5 4. h4 h5 5. Bg5 Qb6 6. Bd3 Bxd3 7. Qxd3 Qxb2
8. e6 Qxa1 *

[d]rn2kbnr/pp2ppp1/2p1P3/3p2Bp/3P3P/3Q4/P1P2PP1/qN2K1NR w Kkq - 0 9