Hard testposition from master Om

Discussion of anything and everything relating to chess playing software and machines.

Moderators: hgm, Rebel, chrisw

fastgm
Posts: 818
Joined: Mon Aug 19, 2013 6:57 pm

Re: Hard testposition from master Om

Post by fastgm »

stockfish_syzygy_14090802_x64_modern
Opteron 6376, 16 Cores @ 2.3 GHz, 8192 MB Hash

Code: Select all

 40/63-	35:14	 24.928.189k	11.791k	-1,51	1.Kg2 cxd4 2.cxd4 Td8 3.Td1 Kg8 4.Db2 Sfxd4 5.Lh5 Dd5 6.Lxf7+ Kh8 7.Lg6 b5 8.f3 Le7 9.Sd6 Lxd6 10.exd6 Dxd6 11.Tg4
 40/63+	37:51	 26.785.993k	11.794k	-1,39	1.Txf5 exf5
 40/63+	38:34	 27.231.451k	11.767k	-1,30	1.Txf5 exf5
 40/63+	39:00	 27.488.459k	11.746k	-1,18	1.Txf5
 40/63+	39:34	 27.869.442k	11.735k	-1,03	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	40:00	 28.164.170k	11.735k	-0,81	1.Txf5 Sxd4+ 2.cxd4 exf5
 40/63+	40:30	 28.520.438k	11.733k	-0,51	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	41:06	 28.948.465k	11.739k	-0,10	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4 fxe4
 40/63+	42:46	 30.122.755k	11.737k	+0,44	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	44:18	 31.258.196k	11.758k	+1,21	1.Txf5 cxd4 2.Th5 Dd5 3.Kg2 Dxe4+ 4.Lf3 Dg6+ 5.Kh1 dxc3 6.Dxc3
 40/63+	47:34	 33.612.804k	11.774k	+2,27	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 cxd4 5.Lh5+ Kh6 6.Lf3+ Kg6 7.cxd4 Te6
 40/63+	49:08	 34.792.264k	11.801k	+3,72	1.Txf5 Kh8 2.Th5 cxd4 3.Dg5 Se7
 40/63+	56:16	 40.024.895k	11.855k	+5,71	1.Txf5 Kh8 2.Th5 cxd4 3.Dg5 Se7 4.Txh6+
 40/64	1:14:28	53.880.445k	12.058k	+6,39	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4 Dc6 6.d5 fxe4 7.dxc6 Txe5 8.Kxe5 bxc6 9.Lh5+ Kg5 10.Lxf7 Kg4 11.Kxe4 a5 12.Tg1+ Kh3 13.Lb3 c4 14.Lxc4 c5 15.Tg6 Kh2 16.Lb3 Kh1 17.f4 Kh2 18.Tc6 c4
...
 42/64+  1:30:49	66.160.368k	12.141k	+6,79	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4
Top
User avatar
Eelco de Groot
Posts: 4567
Joined: Sun Mar 12, 2006 2:40 am
Full name:   

Re: Hard testposition from master Om

Post by Eelco de Groot »

fastgm wrote:stockfish_syzygy_14090802_x64_modern
Opteron 6376, 16 Cores @ 2.3 GHz, 8192 MB Hash

Code: Select all

 40/63-	35:14	 24.928.189k	11.791k	-1,51	1.Kg2 cxd4 2.cxd4 Td8 3.Td1 Kg8 4.Db2 Sfxd4 5.Lh5 Dd5 6.Lxf7+ Kh8 7.Lg6 b5 8.f3 Le7 9.Sd6 Lxd6 10.exd6 Dxd6 11.Tg4
 40/63+	37:51	 26.785.993k	11.794k	-1,39	1.Txf5 exf5
 40/63+	38:34	 27.231.451k	11.767k	-1,30	1.Txf5 exf5
 40/63+	39:00	 27.488.459k	11.746k	-1,18	1.Txf5
 40/63+	39:34	 27.869.442k	11.735k	-1,03	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	40:00	 28.164.170k	11.735k	-0,81	1.Txf5 Sxd4+ 2.cxd4 exf5
 40/63+	40:30	 28.520.438k	11.733k	-0,51	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	41:06	 28.948.465k	11.739k	-0,10	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4 fxe4
 40/63+	42:46	 30.122.755k	11.737k	+0,44	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	44:18	 31.258.196k	11.758k	+1,21	1.Txf5 cxd4 2.Th5 Dd5 3.Kg2 Dxe4+ 4.Lf3 Dg6+ 5.Kh1 dxc3 6.Dxc3
 40/63+	47:34	 33.612.804k	11.774k	+2,27	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 cxd4 5.Lh5+ Kh6 6.Lf3+ Kg6 7.cxd4 Te6
 40/63+	49:08	 34.792.264k	11.801k	+3,72	1.Txf5 Kh8 2.Th5 cxd4 3.Dg5 Se7
 40/63+	56:16	 40.024.895k	11.855k	+5,71	1.Txf5 Kh8 2.Th5 cxd4 3.Dg5 Se7 4.Txh6+
 40/64	1:14:28	53.880.445k	12.058k	+6,39	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4 Dc6 6.d5 fxe4 7.dxc6 Txe5 8.Kxe5 bxc6 9.Lh5+ Kg5 10.Lxf7 Kg4 11.Kxe4 a5 12.Tg1+ Kh3 13.Lb3 c4 14.Lxc4 c5 15.Tg6 Kh2 16.Lb3 Kh1 17.f4 Kh2 18.Tc6 c4
...
 42/64+  1:30:49	66.160.368k	12.141k	+6,79	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4
Thanks for running it Andreas!

Here is my own result with a modified Stockfish but the modification did not help much. I am not sure exactly what sub-version was used but it does not matter a lot for the result probably.

4rb2/1p1q1ppk/p1n1p2p/2p1Pn2/3PNR2/2P2K2/P2QBP2/6R1 w - -

Engine: Sf20140810 MOD MP (Q6700, 4 threads, 32 bit, 512 MB)
by Tord Romstad, Marco Costalba and Joona Kiiski

16/19 0:01 -2.11 1.Kg2 cxd4 2.Ng3 g5 3.Re4 Bg7 4.Rh1 Nxe5
5.cxd4 Nxg3 6.fxg3 Qd5 7.Qe3 f5
8.dxe5 Qxe4+ 9.Qxe4 fxe4 (2.725.522) 2129

.
.
.
.

37/44 60:41 -1.54 1.Kg2 cxd4 2.cxd4 Rd8 3.Rd1 Nfxd4
4.Nd6 Nf5 5.Qc2 Bxd6 6.exd6 (10.588.945.009) 2907

38/44 78:09 -1.48++ 1.Kg2 cxd4 2.cxd4 (13.683.148.566) 2917

38/44 82:37 -1.60-- 1.Kg2 cxd4 2.cxd4 Rd8 3.Rd1 Kg8
4.Qb2 Nfxd4 5.Bh5 (14.466.367.459) 2917

38/46 95:18 -1.51 1.Kg2 cxd4 2.cxd4 Rd8 3.Rd1 Nfxd4
4.Nd6 Nf5 5.Qc2 Bxd6 6.exd6 Kg8
7.Bf3 Ne5 8.Rb4 b5 9.Qc7 Nxf3
10.Kxf3 e5 11.Rd5 f6 12.a4 Nd4+
13.Kg3 Kf8 14.axb5 (16.731.955.769) 2926

39/46 108:18 -1.45++ 1.Kg2 cxd4 (19.104.684.471) 2939

39/46 119:45 -1.39++ 1.Rxf5 exf5 2.Qxh6+ Kxh6 3.Rh1+ Kg6
4.Kf4 Re6 5.Rh8 (21.208.854.571) 2951

39/46 121:30 -1.31++ 1.Rxf5 (21.533.118.820) 2953

39/46 123:47 -1.19++ 1.Rxf5 Nxd4+ 2.cxd4 (21.954.800.190) 2955

39/50 125:50 -1.03++ 1.Rxf5 exf5 2.Qxh6+ Kxh6 3.Rh1+ Kg6
4.Kf4 Re6 (22.318.501.168) 2955

39/50 127:58 -0.81++ 1.Rxf5 exf5 2.Qxh6+ Kxh6 3.Rh1+ Kg6
4.Kf4 Re6 5.Rh8 (22.703.883.803) 2956

39/50 130:34 -0.51++ 1.Rxf5 (23.168.213.347) 2957

39/50 132:38 -0.11++ 1.Rxf5 exf5 2.Qxh6+ Kxh6 3.Rh1+ Kg6
4.Kf4 Re6 5.Rh8 (23.548.565.112) 2958

39/50 139:50 +0.44++ 1.Rxf5 (24.929.674.121) 2971

39/50 142:28 +1.21++ 1.Rxf5 Nxd4+ 2.cxd4 (25.415.433.220) 2973

39/50 145:14 +2.26++ 1.Rxf5 Kh8 2.Rf6 Qd5 3.Qf4 cxd4
4.Rxh6+ Kg8 (25.930.592.261) 2975

39/50 156:11 +3.71++ 1.Rxf5 Nxd4+ 2.cxd4 exf5 3.Qxh6+ Kxh6
4.Rh1+ Kg6 5.Kf4 Qe6 (27.933.679.704) 2980

39/50 166:46 +5.15 1.Rxf5 Nxd4+ 2.cxd4 exf5 3.Qxh6+ Kxh6
4.Rh1+ Kg6 5.Kf4 Qc6 6.d5 fxe4
7.dxc6 Rxe5 8.Kxe5 bxc6 9.Bxa6 Be7
10.Rg1+ Kh7 11.Bc4 Kg8 12.Kxe4 Kf8
13.Rd1 Bf6 14.Rd7 (29.790.323.285) 2977

40/50 178:14 +5.15 1.Rxf5 Nxd4+ 2.cxd4 exf5 3.Qxh6+ Kxh6
4.Rh1+ Kg6 5.Kf4 Qc6 6.d5 fxe4
7.dxc6 Rxe5 8.Kxe5 bxc6 9.Bxa6 Be7
10.Rg1+ Kh7 11.Bc4 Kg8 12.Kxe4 Kf8
13.Rd1 Bf6 14.Rd7 (31.788.073.213) 2972

best move: Rf4xf5 time: 178:15.569 min n/s: 2.972.389 nodes: 31.788.073.213
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
Top
zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Hard testposition from master Om

Post by zullil »

fastgm wrote:stockfish_syzygy_14090802_x64_modern
Opteron 6376, 16 Cores @ 2.3 GHz, 8192 MB Hash

Code: Select all

 40/63-	35:14	 24.928.189k	11.791k	-1,51	1.Kg2 cxd4 2.cxd4 Td8 3.Td1 Kg8 4.Db2 Sfxd4 5.Lh5 Dd5 6.Lxf7+ Kh8 7.Lg6 b5 8.f3 Le7 9.Sd6 Lxd6 10.exd6 Dxd6 11.Tg4
 40/63+	37:51	 26.785.993k	11.794k	-1,39	1.Txf5 exf5
 40/63+	38:34	 27.231.451k	11.767k	-1,30	1.Txf5 exf5
 40/63+	39:00	 27.488.459k	11.746k	-1,18	1.Txf5
 40/63+	39:34	 27.869.442k	11.735k	-1,03	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	40:00	 28.164.170k	11.735k	-0,81	1.Txf5 Sxd4+ 2.cxd4 exf5
 40/63+	40:30	 28.520.438k	11.733k	-0,51	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	41:06	 28.948.465k	11.739k	-0,10	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4 fxe4
 40/63+	42:46	 30.122.755k	11.737k	+0,44	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	44:18	 31.258.196k	11.758k	+1,21	1.Txf5 cxd4 2.Th5 Dd5 3.Kg2 Dxe4+ 4.Lf3 Dg6+ 5.Kh1 dxc3 6.Dxc3
 40/63+	47:34	 33.612.804k	11.774k	+2,27	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 cxd4 5.Lh5+ Kh6 6.Lf3+ Kg6 7.cxd4 Te6
 40/63+	49:08	 34.792.264k	11.801k	+3,72	1.Txf5 Kh8 2.Th5 cxd4 3.Dg5 Se7
 40/63+	56:16	 40.024.895k	11.855k	+5,71	1.Txf5 Kh8 2.Th5 cxd4 3.Dg5 Se7 4.Txh6+
 40/64	1:14:28	53.880.445k	12.058k	+6,39	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4 Dc6 6.d5 fxe4 7.dxc6 Txe5 8.Kxe5 bxc6 9.Lh5+ Kg5 10.Lxf7 Kg4 11.Kxe4 a5 12.Tg1+ Kh3 13.Lb3 c4 14.Lxc4 c5 15.Tg6 Kh2 16.Lb3 Kh1 17.f4 Kh2 18.Tc6 c4
...
 42/64+  1:30:49	66.160.368k	12.141k	+6,79	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4
Depth 41 here. No tablebases.

Code: Select all

info depth 41 seldepth 65 score cp -140 lowerbound nodes 32446476349 nps 20972625 time 1547087 multipv 1 pv f4f5 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 e8b8 e4c5
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp -134 lowerbound nodes 32696892958 nps 20909524 time 1563732 multipv 1 pv f4f5 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 e8b8 e4c5
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp -125 lowerbound nodes 33046198086 nps 20873475 time 1583167 multipv 1 pv f4f5 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 e8e6 h1h8
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp -114 lowerbound nodes 33615038259 nps 20892154 time 1608979 multipv 1 pv f4f5 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 e8e6 h1h8
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp -98 lowerbound nodes 33962946892 nps 20885199 time 1626173 multipv 1 pv f4f5 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 e8e6 h1h8
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp -76 lowerbound nodes 34538068648 nps 20893149 time 1653081 multipv 1 pv f4f5 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 e8e6 h1h8
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp -46 lowerbound nodes 36285884706 nps 20944064 time 1732514 multipv 1 pv f4f5 c6d4 c3d4 e6f5
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp -6 lowerbound nodes 36745185641 nps 20910678 time 1757245 multipv 1 pv f4f5 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 e8e6 h1h8
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp 49 lowerbound nodes 38465311241 nps 21014507 time 1830417 multipv 1 pv f4f5 c6d4 c3d4
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp 126 lowerbound nodes 39660160701 nps 21031951 time 1885710 multipv 1 pv f4f5 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 c5d4 e2h5 g6h6 h5f3 h6g6 c3d4 c6d4
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp 231 lowerbound nodes 41158586906 nps 21103417 time 1950328 multipv 1 pv f4f5 c6d4 c3d4 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 f5e4
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp 376 lowerbound nodes 43871607646 nps 21203088 time 2069114 multipv 1 pv f4f5 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 c6d4
info depth 41 currmove f4f5 currmovenumber 1
info depth 41 seldepth 65 score cp 575 lowerbound nodes 48850890731 nps 21368817 time 2286083 multipv 1 pv f4f5 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 c6d4
Top
User avatar
Master Om
Posts: 450
Joined: Wed Nov 24, 2010 10:57 am
Location: INDIA

Re: Hard testposition from master Om

Post by Master Om »

shrapnel wrote:HA !
Komodo 8 gets the correct Rxf5 in one second FLAT on my (rather superb ! ) computer ! Beat THAT !
Stockfish finds it very late...another weakness discovered in the otherwise formidable Stockfish !
Actually, for a long time Stockfish recommends the losing 1. Kg2...HAHHAHA
Image
What was so hard about it anyway, except maybe for BLIND-FISH ! :lol:
I posted it because the regular Stockfish does not find the key move but all other engines do. It does not mean that Stockfish does not find it.

New game
[d]4rb2/1p1q1ppk/p1n1p2p/2p1Pn2/3PNR2/2P2K2/P2QBP2/6R1 w - - 0 1

Analysis by StockfishRW_VD 270514 SSE4.2 AVX:

1.Rxf5 Nxd4+ 2.cxd4 exf5 3.Qxh6+ Kxh6 4.Rh1+ Kg6 5.Kf4 Qc6 6.d5 fxe4 7.dxc6 Rxe5 8.Kxe5 bxc6 9.Bh5+ Kg5 10.Bxf7 Be7
+- (3.00 ++) Depth: 16/27 00:00:13 138mN
(Prakash, Bhubaneswar 12.09.2014)


And after a while.....


New game
[d]4rb2/1p1q1ppk/p1n1p2p/2p1Pn2/3PNR2/2P2K2/P2QBP2/6R1 w - - 0 1

Analysis by StockfishRW_VD 270514 SSE4.2 AVX:

1.Rxf5 Nxd4+ 2.cxd4 exf5 3.Qxh6+ Kxh6 4.Rh1+ Kg6 5.Kf4 Qc6 6.d5 fxe4 7.dxc6 Rxe5 8.Kxe5 bxc6 9.Bh5+ Kg5 10.Bxf7 Be7 11.Rg1+ Kh6 12.Rg6+ Kh7 13.Rxc6 Bf6+ 14.Kxe4 Bd4 15.Rxa6
+- (3.48) Depth: 20/34 00:01:52 954mN
(Prakash, Bhubaneswar 12.09.2014)
Always Expect the Unexpected
Top
Uri Blass
Posts: 10297
Joined: Thu Mar 09, 2006 12:37 am
Location: Tel-Aviv Israel

Re: Hard testposition from master Om

Post by Uri Blass »

Eelco de Groot wrote:
fastgm wrote:stockfish_syzygy_14090802_x64_modern
Opteron 6376, 16 Cores @ 2.3 GHz, 8192 MB Hash

Code: Select all

 40/63-	35:14	 24.928.189k	11.791k	-1,51	1.Kg2 cxd4 2.cxd4 Td8 3.Td1 Kg8 4.Db2 Sfxd4 5.Lh5 Dd5 6.Lxf7+ Kh8 7.Lg6 b5 8.f3 Le7 9.Sd6 Lxd6 10.exd6 Dxd6 11.Tg4
 40/63+	37:51	 26.785.993k	11.794k	-1,39	1.Txf5 exf5
 40/63+	38:34	 27.231.451k	11.767k	-1,30	1.Txf5 exf5
 40/63+	39:00	 27.488.459k	11.746k	-1,18	1.Txf5
 40/63+	39:34	 27.869.442k	11.735k	-1,03	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	40:00	 28.164.170k	11.735k	-0,81	1.Txf5 Sxd4+ 2.cxd4 exf5
 40/63+	40:30	 28.520.438k	11.733k	-0,51	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	41:06	 28.948.465k	11.739k	-0,10	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4 fxe4
 40/63+	42:46	 30.122.755k	11.737k	+0,44	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 Te6 5.Th8
 40/63+	44:18	 31.258.196k	11.758k	+1,21	1.Txf5 cxd4 2.Th5 Dd5 3.Kg2 Dxe4+ 4.Lf3 Dg6+ 5.Kh1 dxc3 6.Dxc3
 40/63+	47:34	 33.612.804k	11.774k	+2,27	1.Txf5 exf5 2.Dxh6+ Kxh6 3.Th1+ Kg6 4.Kf4 cxd4 5.Lh5+ Kh6 6.Lf3+ Kg6 7.cxd4 Te6
 40/63+	49:08	 34.792.264k	11.801k	+3,72	1.Txf5 Kh8 2.Th5 cxd4 3.Dg5 Se7
 40/63+	56:16	 40.024.895k	11.855k	+5,71	1.Txf5 Kh8 2.Th5 cxd4 3.Dg5 Se7 4.Txh6+
 40/64	1:14:28	53.880.445k	12.058k	+6,39	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4 Dc6 6.d5 fxe4 7.dxc6 Txe5 8.Kxe5 bxc6 9.Lh5+ Kg5 10.Lxf7 Kg4 11.Kxe4 a5 12.Tg1+ Kh3 13.Lb3 c4 14.Lxc4 c5 15.Tg6 Kh2 16.Lb3 Kh1 17.f4 Kh2 18.Tc6 c4
...
 42/64+  1:30:49	66.160.368k	12.141k	+6,79	1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4
Thanks for running it Andreas!

Here is my own result with a modified Stockfish but the modification did not help much. I am not sure exactly what sub-version was used but it does not matter a lot for the result probably.

4rb2/1p1q1ppk/p1n1p2p/2p1Pn2/3PNR2/2P2K2/P2QBP2/6R1 w - -
You simply did not modify stockfish correctly
The problem is obvious for me.

stockfish use very aggresive null move pruning
Stockfish can solve it clearly faster
if you change

Depth R = 3 * ONE_PLY
+ depth / 4
+ (abs(beta) < VALUE_KNOWN_WIN ? int(eval - beta) / PawnValueMg *

ONE_PLY: DEPTH_ZERO);

to

Depth R = 3 * ONE_PLY
+ depth / 4;

Additional note is that stockfish does not evaluate king attack when the attacker has no queens and I am not sure if it is a good idea.

a king attack clearly can happen when the attacker has no queens so
maybe it is better to remove
if (pos.count<QUEEN>(Us)) in evaluate.cpp


It may be also better to remove null pruning when the opponent control all the squares that the king can goto them.
Top
peter
Posts: 3186
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: Hard testposition from master Om

Post by peter »

Uri Blass wrote: stockfish use very aggresive null move pruning
Hi Uri!

And that is why SF RW VD (Rockwood Valentine's Day) is so much faster here, as Master Om showed already in a posting above.
It doesn't use nullmove at all, as far as I know.

BTW Sting succeeds also:

4rb2/1p1q1ppk/p1n1p2p/2p1Pn2/3PNR2/2P2K2/P2QBP2/6R1 w - - 0 1

Analysis by Sting SF 4.7:

1.Tfg4
-/+ (-1.45 --) Tiefe: 7 00:00:00 11kN
...
1.Kg2 cxd4 2.cxd4 Scxd4 3.Lh5 Kg8 4.Tb1 Dd5 5.Kg1
-+ (-1.89) Tiefe: 9/15 00:00:01 99kN
...
1.Txf5
-+ (-1.85 ++) Tiefe: 21 00:00:55 48494kN
...
1.Txf5 Sxd4+ 2.cxd4 exf5 3.Dxh6+ Kxh6 4.Th1+ Kg6 5.Kf4 Dc6 6.d5 fxe4 7.dxc6 Txe5 8.Kxe5 bxc6 9.Lh5+ Kg5 10.Lxf7 Kg4 11.Kxe4 a5 12.Tg1+ Kh3 13.Kf3 Kh2 14.Tg2+ Kh3 15.Tg5 Kh2 16.Tg4 Kh3 17.Le6 Kh2 18.Tg2+ Kh1 19.Lc4 a4 20.a3 Ld6 21.Txg7 Le5 22.Te7
+- (6.82) Tiefe: 30/49 00:03:28 1750MN

Sorry for german abbrevations, forget to switch now and then before starting engine
Peter.
Top
gladius
Posts: 568
Joined: Tue Dec 12, 2006 10:10 am
Full name: Gary Linscott

Re: Hard testposition from master Om

Post by gladius »

Eelco de Groot wrote:[D]4rb2/1p1q1ppk/p1n1p2p/2p1Pn2/3PNR2/2P2K2/P2QBP2/6R1 w - -

Does Stockfish find the correct move ?

Warning: not easy for the fish!
This is indeed a hard problem for SF. There are a few issues that contribute to it. First, you have to sac the rook, then then the queen to draw the king out into danger. Then there is a quiet king move, towards the center no less, to allow the bishop to come in and create the mating threats.

The combination of being way down in material, along with a quiet king move is just too much to overcome. There are lots of ideas that could help with this position, it will be interesting to see if any of them will be a strength gain.
Top
User avatar
Bloodbane
Posts: 154
Joined: Thu Oct 03, 2013 4:17 pm

Re: Hard testposition from master Om

Post by Bloodbane »

This is a pretty interesting position. Even Hakkapeliitta can find the right move in about two minutes on an old laptop and it's rating is only about 2600.

Hakkapeliitta 120914, (C) 2013-2014 Mikko Aarnos
position fen 4rb2/1p1q1ppk/p1n1p2p/2p1Pn2/3PNR2/2P2K2/P2QBP2/6R1 w - -
setoption name Hash value 512
go infinite
info depth 1 score cp -102 time 0 nodes 2 nps 2000 tbhits 0 pv d4c5
info depth 1 score cp -95 time 10 nodes 19 nps 1000 tbhits 0 pv a2a3
info depth 1 score cp -89 time 18 nodes 60 nps 3000 tbhits 0 pv e2c4
info depth 1 score cp 1 time 31 nodes 118 nps 3000 tbhits 0 pv f4g4
info depth 1 score cp 1 time 43 nodes 150 nps 3000 tbhits 0 pv f4g4
info depth 2 score cp 1 time 49 nodes 201 nps 4000 tbhits 0 pv f4g4 c5d4
info depth 2 score cp 1 time 57 nodes 453 nps 7000 tbhits 0 pv f4g4 c5d4
info depth 3 score cp -25 time 64 nodes 898 nps 13000 tbhits 0 pv f4g4 d7d5 d4c5

info depth 3 score cp -25 time 70 nodes 1398 nps 19000 tbhits 0 pv f4g4 d7d5 d4c
5
info depth 4 score cp -55 time 76 nodes 2516 nps 32000 tbhits 0 pv f4g4 c5d4 c3d
4
info depth 4 score cp -55 time 83 nodes 3815 nps 45000 tbhits 0 pv f4g4 c5d4 c3d
4
info depth 5 score cp -64 time 89 nodes 5153 nps 57000 tbhits 0 pv f4g4 c5d4 d2f
4 h7h8 e2c4
info depth 5 score cp -64 time 96 nodes 8138 nps 83000 tbhits 0 pv f4g4 c5d4 d2f
4 h7h8 e2c4
info depth 6 score cp -109 time 106 nodes 16422 nps 153000 tbhits 0 pv f3g2 c5d4
c3d4 c6d4 g2h1 f8e7
info depth 6 score cp -109 time 116 nodes 24375 nps 208000 tbhits 0 pv f3g2 c5d4
c3d4 c6d4 g2h1 f8e7
info depth 7 score cp -124 time 126 nodes 31696 nps 249000 tbhits 0 pv f3g2 c5d4
c3d4 f8b4 d2b2 f5d4 g1d1
info depth 7 score cp -124 time 150 nodes 63039 nps 417000 tbhits 0 pv f3g2 c5d4
c3d4 f8b4 d2b2 f5d4 g1d1
info depth 8 score cp -127 time 160 nodes 69309 nps 430000 tbhits 0 pv f3g2 c5d4
c3d4 f8b4 d2b2 f5d4 e2c4
info depth 8 score cp -127 time 183 nodes 99557 nps 541000 tbhits 0 pv f3g2 c5d4
c3d4 f8b4 d2b2 f5d4 e2c4
info depth 9 score cp -134 time 207 nodes 127518 nps 613000 tbhits 0 pv f3g2 c5d
4 g2h3 h7h8 c3d4 f5d4 e4c3 f8b4 f4e4
info depth 9 score cp -134 time 239 nodes 171891 nps 716000 tbhits 0 pv f3g2 c5d
4 g2h3 h7h8 c3d4 f5d4 e4c3 f8b4 f4e4
info depth 10 score cp -142 time 263 nodes 204158 nps 773000 tbhits 0 pv f3g2 c5
d4 g2h3 d7d5 c3d4 c6d4 e2h5 d5e5 h5f7 f8b4
info depth 10 score cp -142 time 323 nodes 300303 nps 926000 tbhits 0 pv f3g2 c5
d4 g2h3 d7d5 c3d4 c6d4 e2h5 d5e5 h5f7 f8b4
info depth 11 score cp -149 time 391 nodes 415562 nps 1060000 tbhits 0 pv f3g2 c
5d4 c3d4 f8b4 d2d3 c6d4 g1b1
info depth 11 score cp -149 time 508 nodes 615597 nps 1209000 tbhits 0 pv f3g2 c
5d4 c3d4 f8b4 d2d3 c6d4 g1b1
info depth 12 score cp -145 time 629 nodes 835671 nps 1326000 tbhits 0 pv f3g2 c
5d4 c3d4 f8b4 d2d3 c6d4 g1b1 b4e7 d3c4 d4e2
info depth 12 score cp -145 time 768 nodes 1076483 nps 1399000 tbhits 0 pv f3g2
c5d4 c3d4 f8b4 d2d3 c6d4 g1b1 b4e7 d3c4 d4e2
info depth 13 score cp -141 time 923 nodes 1360481 nps 1472000 tbhits 0 pv f3g2
c5d4 c3d4 f8b4 d2d3 c6d4 e2h5 d7d5 h5f7 d5e5 f7e8 e5f4
info depth 13 score cp -141 time 1218 nodes 1881959 nps 1543000 tbhits 0 pv f3g2
c5d4 c3d4 f8b4 d2d3 c6d4 e2h5 d7d5 h5f7 d5e5 f7e8 e5f4
info depth 14 score cp -147 time 1522 nodes 2458158 nps 1614000 tbhits 0 pv f3g2
c5d4 c3d4 f8b4 d2d3 c6d4 e2f3 d7e7 f3g4
info depth 14 score cp -147 time 2205 nodes 3716238 nps 1684000 tbhits 0 pv f3g2
c5d4 c3d4 f8b4 d2d3 c6d4 e2f3 d7e7 f3g4
info depth 15 score cp -156 time 2893 nodes 5009112 nps 1730000 tbhits 0 pv f3g2
c5d4 c3d4 f8b4 d2b2 f5d4 e4d6 b4d6 e5d6 d4f5 f4g4 d7d6 b2b7 c6e5 g1d1
info depth 15 score cp -156 time 4389 nodes 7834251 nps 1784000 tbhits 0 pv f3g2
c5d4 c3d4 f8b4 d2b2 f5d4 e4d6 b4d6 e5d6 d4f5 f4g4 d7d6 b2b7 c6e5 g1d1
info depth 16 score cp -162 time 5948 nodes 10770069 nps 1810000 tbhits 0 pv f3g
2 c5d4 c3d4 f8b4 d2d3 d7d5 a2a3
info depth 16 score cp -162 time 8953 nodes 16406356 nps 1832000 tbhits 0 pv f3g
2 c5d4 c3d4 f8b4 d2d3 d7d5 a2a3
info depth 17 score cp -164 time 12936 nodes 23755192 nps 1836000 tbhits 0 pv f3
g2 c5d4 c3d4 f8b4 d2d3 d7d5 g1b1 e8d8 b1b2 h7g8 a2a3 b4e7 d3c4 c6d4 c4d5 e6d5 e2
g4
info depth 17 score cp -164 time 33248 nodes 62087608 nps 1867000 tbhits 0 pv f3
g2 c5d4 c3d4 f8b4 d2d3 d7d5 g1b1 e8d8 b1b2 h7g8 a2a3 b4e7 d3c4 c6d4 c4d5 e6d5 e2
g4
info depth 18 score cp -154 time 43794 nodes 81753147 nps 1866000 tbhits 0 pv f3
g2 c5d4 c3d4 f8b4 d2b2 f5d4 g2f1 h7h8 g1g7 h8g7 e4f6 d7d8 f4g4 g7h8 f6e8 d8e8
info depth 18 score cp -154 time 52954 nodes 98710801 nps 1864000 tbhits 0 pv f3
g2 c5d4 c3d4 f8b4 d2b2 f5d4 g2f1 h7h8 g1g7 h8g7 e4f6 d7d8 f4g4 g7h8 f6e8 d8e8
info depth 19 score cp -143 time 94381 nodes 175681896 nps 1861000 tbhits 0 pv f
3g2 c5d4 c3d4 h7h8 g1d1 e8d8 e4g3 c6e5
info depth 19 score cp -104 lowerbound time 130179 nodes 243568708 nps 1871000
tbhits 0 pv f4f5 c6d4
info depth 19 score cp -54 lowerbound time 143054 nodes 268447363 nps 1876000 t
bhits 0 pv f4f5 c6d4
info depth 19 score cp 46 lowerbound time 164816 nodes 309865286 nps 1880000 tb
hits 0 pv f4f5 c6d4
info depth 19 score cp 245 time 235892 nodes 441211835 nps 1870000 tbhits 0 pv f
4f5 c6d4 c3d4 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 d7c6
info depth 19 score cp 245 time 236537 nodes 442326900 nps 1870000 tbhits 0 pv f
4f5 c6d4 c3d4 e6f5 d2h6 h7h6 g1h1 h6g6 f3f4 d7c6
stop
info time 239359 nodes 446684933 nps 1866000 tbhits 0
bestmove f4f5
Functional programming combines the flexibility and power of abstract mathematics with the intuitive clarity of abstract mathematics.
https://github.com/mAarnos
Top
jhellis3
Posts: 546
Joined: Sat Aug 17, 2013 12:36 am

Re: Hard testposition from master Om

Post by jhellis3 »

Ok, I created a branch which should help finding threats against the king earlier with as little ELO loss as I could manage. It also contains some cosmetic score smoothing, which Master Om previously mentioned he would appreciate. By all means, disregard this if you don't want it.


Branch: https://github.com/jhellis3/Stockfish/tree/staticfish

Commit: https://github.com/jhellis3/Stockfish/c ... 5bada729c4


Disclaimer: It will be weaker than SF, but should be fine for analysis or puzzle positions.
Top
User avatar
Master Om
Posts: 450
Joined: Wed Nov 24, 2010 10:57 am
Location: INDIA

Re: Hard testposition from master Om

Post by Master Om »

jhellis3 wrote:Ok, I created a branch which should help finding threats against the king earlier with as little ELO loss as I could manage. It also contains some cosmetic score smoothing, which Master Om previously mentioned he would appreciate. By all means, disregard this if you don't want it.


Branch: https://github.com/jhellis3/Stockfish/tree/staticfish

Commit: https://github.com/jhellis3/Stockfish/c ... 5bada729c4


Disclaimer: It will be weaker than SF, but should be fine for analysis or puzzle positions.

That is awesome Joseph!! . That's awesome. Need one who can compile. :D
Always Expect the Unexpected
Top

Return to “Computer Chess Club: General Topics”