Stockfish endgame weakness

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

Moderator: Ras

BBauer
Posts: 658
Joined: Wed Mar 08, 2006 8:58 pm

Stockfish endgame weakness

Post by BBauer »

Stockfish is completely helpless with the following position from
"The Chess World", 1865
[d]8/1Q4K1/8/8/8/2p5/8/2k5 w - - 0 24

Code: Select all

  30	01:40	 424.489.510	4.231.692	+89,19	Kg7f6 c3c2 Kf6e5 Kc1d2 Qb7b2 Kd2d1 Qb2b3 Kd1d2 Qb3d5+ Kd2e1 Qd5h1+ Ke1d2 Qh1h6+ Kd2d1 Qh6d6+ Kd1e2 Qd6a6+ Ke2d2 Qa6a2 Kd2c3 Qa2a3+ Kc3d2 Qa3b4+ Kd2d1 Qb4a4 Kd1d2 Qa4d4+ Kd2e2 Qd4c3 Ke2d1 Qc3d3+ Kd1c1 Ke5f5 Kc1b2 Qd3e2 Kb2b1 Qe2e4 Kb1b2 Qe4b4+ Kb2a1 Qb4a3+ Ka1b1 Qa3b3+ Kb1a1 Qb3xc2
  31	01:56	 491.575.029	4.226.893	+89,29	Kg7f6 c3c2 Kf6e5 Kc1d2 Qb7b2 Kd2d1 Qb2b3 Kd1d2 Qb3d5+ Kd2e1 Qd5h1+ Ke1d2 Qh1h6+ Kd2d1 Qh6d6+ Kd1e2 Qd6a6+ Ke2d2 Qa6a2 Kd2c3 Qa2a3+ Kc3d2 Qa3b4+ Kd2d1 Qb4d4+ Kd1e2 Qd4c3 Ke2d1 Qc3d3+ Kd1c1 Qd3e2 Kc1b1 Qe2b5+ Kb1a2 Qb5c5 Ka2b2 Qc5b6+ Kb2a2 Qb6a5+ Ka2b2 Qa5b4+ Kb2a2 Qb4c3 Ka2b1 Qc3b3+ Kb1a1 Qb3xc2
  32	02:14	 564.525.354	4.197.120	+89,29	Kg7f6 c3c2 Kf6e5 Kc1d2 Qb7b2 Kd2d1 Qb2b3 Kd1d2 Qb3d5+ Kd2e1 Qd5h1+ Ke1d2 Qh1h6+ Kd2d1 Qh6d6+ Kd1e2 Qd6a6+ Ke2d2 Qa6a2 Kd2c3 Qa2a3+ Kc3d2 Qa3b4+ Kd2d1 Qb4d4+ Kd1e2 Qd4c3 Ke2d1 Qc3d3+ Kd1c1 Ke5e4 Kc1b2 Qd3d4+ Kb2b1 Qd4b6+ Kb1a2 Qb6c5 Ka2b1 Qc5b5+ Kb1a2 Qb5c4+ Ka2b2 Qc4b4+ Kb2a1 Qb4c3+ Ka1b1 Qc3b3+ Kb1a1 Qb3xc2
  33	16:34	4.215.687.867	4.238.872	+9,73	Kg7f6 c3c2 Kf6e5 Kc1d2 Qb7b2 Kd2d1 Qb2b3 Kd1d2 Qb3d5+ Kd2e1 Qd5h1+ Ke1d2 Qh1h6+ Kd2d1 Qh6d6+ Kd1e2 Qd6a6+ Ke2d2 Qa6a2 Kd2c3 Qa2a3+ Kc3d2 Qa3b4+ Kd2d1 Qb4d4+ Kd1e2 Qd4c3 Ke2d1 Qc3d3+ Kd1c1 Qd3d4 Kc1b1 Qd4b6+ Kb1a2 Qb6a7+ Ka2b1 Qa7b7+ Kb1a2 Qb7g2 Ka2b3 Qg2d2 Kb3b2 Ke5d4 Kb2b1 Qd2d3 Kb1b2 Qd3c3+ Kb2b1 Qc3b3+ Kb1c1 Kd4e3 Kc1d1 Qb3d3+ Kd1c1 Qd3f1+ Kc1b2 Qf1b5+ Kb2c3 Qb5c6+ Kc3b3 Ke3d2 Kb3b4 Kd2xc2 Kb4a5
  34	28:47	7.111.220.040	4.116.260	+9,01	Kg7f6 c3c2 Kf6e5 Kc1d2 Qb7b2 Kd2d1 Qb2b3 Kd1d2 Qb3d5+ Kd2e1 Qd5h1+ Ke1d2 Qh1h6+ Kd2d1 Qh6d6+ Kd1e2 Qd6a6+ Ke2d2 Qa6a2 Kd2c3 Qa2a3+ Kc3d2 Qa3b4+ Kd2d1 Qb4d4+ Kd1c1 Ke5d5 Kc1b1 Qd4e4 Kb1b2 Qe4b4+ Kb2a1 Qb4a4+ Ka1b2 Qa4b5+ Kb2a3 Qb5c5+ Ka3b2 Qc5b6+ Kb2a2 Qb6a7+ Ka2b1 Qa7b8+ Kb1a1 Qb8e5+ Ka1a2 Qe5e1 Ka2b2 Qe1e2 Kb2a1 Qe2f1+ Ka1b2 Qf1f6+ Kb2a2 Qf6c3 Ka2b1 Qc3b3+ Kb1a1 Qb3a4+
  35	37:01	9.052.211.081	4.075.457	+8,68	Kg7f6 c3c2 Kf6e5 Kc1d2 Qb7b2 Kd2d1 Qb2b3 Kd1d2 Qb3d5+ Kd2e1 Qd5h1+ Ke1d2 Qh1h6+ Kd2d1 Qh6d6+ Kd1e2 Qd6a6+ Ke2d2 Qa6a2 Kd2c3 Qa2a3+ Kc3d2 Qa3b4+ Kd2d1 Qb4d4+ Kd1c1 Ke5f4 Kc1b1 Qd4b6+ Kb1a2 Qb6e3 Ka2b2 Qe3e5+ Kb2b1 Qe5b8+ Kb1a2 Qb8c8 Ka2b2 Qc8b7+ Kb2a3 Qb7e7+ Ka3b2 Qe7b4+ Kb2a2 Qb4c3 Ka2b1 Qc3b3+ Kb1a1 Qb3c4 Ka1b2 Qc4b5+ Kb2a2 Qb5a5+ Ka2b2 Qa5d2 Kb2b1 Qd2b4+ Kb1a1 Qb4c3+ Ka1b1
  35+	42:07	10.303.871.171	4.076.091	+49,53	Kg7g6 c3c2 Kg6h5 Kc1d1 Qb7b3 Kd1d2 Qb3b2 Kd2d1 Qb2d4+ Kd1e2 Qd4c3 Ke2d1 Qc3d3+ Kd1c1 Qd3d4 Kc1b1 Qd4b6+ Kb1a2 Qb6a5+ Ka2b2 Qa5b4+ Kb2a2 Qb4d2 Ka2b1 Qd2d3 Kb1c1
  36+	43:19	10.592.674.244	4.074.307	+9,37	Kg7f6 c3c2 Qb7b5 Kc1d2 Qb5b4+ Kd2d1 Qb4d6+ Kd1e2 Qd6c5 Ke2d2 Qc5f2+ Kd2d1 Qf2f3+ Kd1d2 Qf3f4+ Kd2d1 Qf4g4+ Kd1e1 Qg4g3+ Ke1d2 Qg3h2+ Kd2d1 Qh2h5+ Kd1d2 Qh5d5+ Kd2e2 Qd5e5+ Ke2d1 Qe5d4+ Kd1e2 Qd4c3 Ke2d1 Qc3d3+ Kd1c1 Kf6e6 Kc1b2 Qd3d2 Kb2b1 Qd2b4+ Kb1a1 Qb4c3+ Ka1b1 Qc3b3+ Kb1a1 Qb3e3 Ka1b2 Qe3e5+ Kb2b1 Qe5b8+ Kb1a1 Qb8c7 Ka1b2 Qc7b7+ Kb2a1 Qb7c6 Ka1b1 Qc6b6+ Kb1a2 Qb6a5+ Ka2b2 Qa5e5+
  36+	46:18	11.297.579.559	4.065.845	+10,06	Kg7f6 c3c2 Kf6e5 Kc1d2 Qb7b2 Kd2d1 Qb2b3 Kd1d2 Qb3b4+ Kd2d1 Qb4d6+ Kd1e1 Qd6c5 Ke1d2 Qc5a5+ Kd2d1 Qa5d5+ Kd1e1 Qd5e4+ Ke1d2 Qe4f4+ Kd2d1 Qf4d4+ Kd1e2 Qd4c3 Ke2d1 Qc3d3+ Kd1c1 Ke5e4 Kc1b2 Qd3d2 Kb2b1 Qd2b4+ Kb1a1 Qb4a3+ Ka1b1 Qa3b3+ Kb1a1 Qb3c4 Ka1b2 Qc4b4+ Kb2a2 Qb4c3 Ka2b1 Qc3b3+
  36+	46:23	11.313.470.080	4.065.114	+11,43	Kg7f6 c3c2 Kf6e5 Kc1d2 Qb7b2 Kd2d1 Qb2b3 Kd1d2 Qb3b4+ Kd2d1 Qb4d6+ Kd1e1 Qd6c5 Ke1d2 Qc5a5+ Kd2d1 Qa5d5+ Kd1e1 Qd5e4+ Ke1d2 Qe4f4+ Kd2d1 Qf4d4+ Kd1e2 Qd4c3 Ke2d1 Qc3d3+ Kd1c1 Ke5e4 Kc1b2 Qd3d2 Kb2b1 Qd2b4+ Kb1a1 Qb4a3+ Ka1b1 Qa3b3+ Kb1a1 Qb3c4 Ka1b2 Qc4b5+ Kb2a3 Qb5a6+ Ka3b2 Qa6f6+ Kb2b1 Qf6b6+ Kb1a2 Qb6a5+ Ka2b2 Qa5e5+ Kb2b1 Qe5b5+ Kb1a2 Qb5c6 Ka2b2 Qc6f6+
  36+	46:23	11.316.326.946	4.064.886	+14,18	Kg7f6 c3c2 Kf6e5 Kc1d2 Qb7b2 Kd2d1 Qb2b3 Kd1d2 Qb3b4+ Kd2d1 Qb4d6+ Kd1e1 Qd6c5 Ke1d2 Qc5d4+ Kd2e2 Qd4c3 Ke2d1 Qc3d3+ Kd1c1 Ke5d4 Kc1b2 Qd3e2 Kb2a1 Qe2e3 Ka1b1 Qe3b3+ Kb1a1 Qb3a3+ Ka1b1 Qa3b4+ Kb1a1 Qb4e1+ Ka1b2 Qe1c3+ Kb2b1 Qc3b3+
Perhaps bases would help.
Scorpio bitbases are free to use.
Gaviota tablebases are free to use.
Will anything happen on this area for Stockfish in the near future?
kind regards
Bernhard
Top
Edmund
Posts: 670
Joined: Mon Dec 03, 2007 3:01 pm
Location: Barcelona, Spain

Re: Stockfish endgame weakness

Post by Edmund »

This is the sort of knowledge that could easily be hard-coded into the chess program without the need for tablebases:
rook and bishop pawns on the 2nd/7th rank with the king guarding the promotion square and the opponents king too far away are forced draws.
Top
BBauer
Posts: 658
Joined: Wed Mar 08, 2006 8:58 pm

Re: Stockfish endgame weakness

Post by BBauer »

I don't like the idea to introduce special code for special positions.
Bases would help in general.
BTW, in the position I posted the pawn is on the 3. row, not on the 2. (7.)
kind regards
bernhard
Top
Edmund
Posts: 670
Joined: Mon Dec 03, 2007 3:01 pm
Location: Barcelona, Spain

Re: Stockfish endgame weakness

Post by Edmund »

The nalimov compressed files for KQKP use 2.34mb. With the general formula it would take less than 1kb. Furthermore using egtbs at the tips of the tree is very expensive, internal node recognizers are almost free, probably even quicker than the usual eval function.

if you follow the pvs, you will see that the pawn move is very soon to be expected. So a little search is needed and it will see the forced draw. Note also that in this search due to the additional knowledge the EBF will be very low.

BTW I am a big fan of EGTBs myself, but note that in combination with general heuristics they can become even more powerful.
Top
Edmund
Posts: 670
Joined: Mon Dec 03, 2007 3:01 pm
Location: Barcelona, Spain

Re: Stockfish endgame weakness

Post by Edmund »

To be precise, it would take a 3 ply search to see that this position is a forced draw:
1. Qh1+ {1. any other 1 .. c2 draw} Kb2 2. Qb7+ draw by repetition {2. any other 2 .. c2 draw}

regards,
Edmund
Top
Uri Blass
Posts: 11159
Joined: Thu Mar 09, 2006 12:37 am
Location: Tel-Aviv Israel

Re: Stockfish endgame weakness

Post by Uri Blass »

I think that the position is important because it expose a bug in stockfish's search.

The problem is why stockfish get wrong winning scores.
89 pawns at depth 30 means that stockfish is sure that white is winning(it is not a material advantage) and it is not correct that white is winning.

I wonder if there is another free engine that can see the draw by search.
I am interested in engines without knowledge of KQ vs KP draws because you cannot know everything and these engines may be useful for analysis of other endgames.
Top
BBauer
Posts: 658
Joined: Wed Mar 08, 2006 8:58 pm

Re: Stockfish endgame weakness

Post by BBauer »

2 mb is not much today. That would resolve the KQKP problem in general.
I do not believe that
using egtbs at the tips of the tree is very expensive
. That only holds for reading from slow devices.
Of coarse your suggestion may be somewhat faster.
kind regards
Bernhard
Top
User avatar
Michael Diosi
Posts: 672
Joined: Mon Jun 22, 2009 1:37 pm

Re: Stockfish endgame weakness

Post by Michael Diosi »

Hi,


Why do you wonder ?

Code: Select all

FEN: 8/1Q4K1/8/8/8/2p5/8/2k5 w - - 0 24 

Glaurung-w32:
   2	00:00	          87	0	+8,80	24.Kg7-f6 c3-c2 25.Kf6-e5
   2	00:00	         450	0	+8,84	24.Db7-h1+ Kc1-b2 25.Kg7-f6
   3	00:00	       1.230	0	+9,07	24.Db7-h1+ Kc1-b2 25.Dh1-b7+ Kb2-c1 26.Kg7-f6
   4	00:00	       1.923	0	+8,80	24.Db7-h1+ Kc1-b2 25.Dh1-b7+ Kb2-c1 26.Kg7-f6 c3-c2 27.Kf6-e5
   5	00:00	       7.814	488.375	+7,70	24.Db7-h1+ Kc1-b2 25.Dh1-b7+ Kb2-c1 26.Kg7-f6 c3-c2 27.Kf6-e5 Kc1-d2 28.Db7-d5+ Kd2-e3
   5	00:00	      13.358	171.256	+8,01	24.Db7-d5 c3-c2 25.Kg7-f6 Kc1-b2 26.Dd5-b5+ Kb2-a2 27.Db5-c5
   5	00:00	      16.592	212.717	+8,60	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-d5+ Kd2-e1 27.Dd5-c4
   6	00:00	      23.704	252.170	+8,15	24.Kg7-f6 c3-c2 25.Db7-b4 Kc1-d1 26.Db4-d4+ Kd1-e1 27.Dd4-c3+ Ke1-d1 28.Dc3-d3+ Kd1-c1
   7	00:00	      36.403	233.352	+8,94	24.Kg7-f6 c3-c2 25.Db7-b4 Kc1-d1 26.Db4-d4+ Kd1-e1 27.Dd4-c3+ Ke1-d1 28.Dc3-d3+ Kd1-c1 29.Kf6-e5
   8	00:00	      59.567	346.319	+8,94	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Dd4-c3 Kc1-b1 29.Dc3-b3+ Kb1-c1
   9	00:00	      71.794	306.811	+9,43	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Dd4-c3 Kc1-b1 29.Dc3-b3+ Kb1-c1 30.Ke5-d4
  10	00:00	      89.157	356.628	+8,80	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Dd4-c3 Kc1-d1 29.Dc3-d3+ Kd1-c1 30.Ke5-d4 Kc1-b2 31.Dd3-b5+ Kb2-a3
  11	00:00	     129.174	318.162	+9,52	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Dd4-c3 Kc1-d1 29.Dc3-d3+ Kd1-c1 30.Ke5-d4 Kc1-b2 31.Dd3-c3+ Kb2-b1 32.Dc3-b3+ Kb1-c1
  12	00:00	     154.703	366.594	+9,52	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Dd4-c3 Kc1-d1 29.Dc3-d3+ Kd1-c1 30.Ke5-d4 Kc1-b2 31.Dd3-c3+ Kb2-b1 32.Dc3-b3+ Kb1-c1
  13	00:00	     186.126	372.252	+9,88	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Dd4-c3 Kc1-d1 29.Dc3-d3+ Kd1-c1 30.Ke5-d4 Kc1-b2 31.Dd3-c3+ Kb2-b1 32.Dc3-b3+ Kb1-c1 33.Kd4-d3
  14	00:00	     255.383	429.937	+9,13	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Ke5-e4 Kc1-b1 29.Dd4-b4+ Kb1-a1 30.Db4-c5 Ka1-b2 31.Dc5-f2 Kb2-c3 32.Df2-f6+ Kc3-b3 33.Df6-f4
  15	00:00	     306.131	417.072	+8,98	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Ke5-e4 Kc1-b1 29.Dd4-b4+ Kb1-a1 30.Db4-c5 Ka1-b2 31.Dc5-f2 Kb2-c3 32.Df2-f6+ Kc3-b3 33.Df6-a1 Kb3-c4
  16	00:01	     524.719	425.217	+8,82	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Ke5-f4 Kc1-b1 29.Dd4-b4+ Kb1-a2 30.Db4-c3 Ka2-b1 31.Dc3-b3+ Kb1-a1 32.Db3-e3 Ka1-b2 33.De3-e5+ Kb2-b3 34.De5-a1 Kb3-c4
  17	00:02	     946.804	426.680	+8,98	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Ke5-e4 Kc1-b1 29.Dd4-b4+ Kb1-a1 30.Db4-c5 Ka1-b2 31.Dc5-f2 Kb2-b1 32.Df2-b6+ Kb1-a2 33.Db6-a7+ Ka2-b2 34.Da7-g7+ Kb2-b3 35.Dg7-a1 Kb3-c4
  18	00:02	   1.307.588	470.186	+8,94	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Ke5-e4 Kc1-b1 29.Dd4-b4+ Kb1-a1 30.Db4-c5 Ka1-b2 31.Dc5-f2 Kb2-b1 32.Df2-b6+ Kb1-a2 33.Db6-a7+ Ka2-b2 34.Da7-b7+ Kb2-a2 35.Db7-d5+ Ka2-b2 36.Dd5-b5+ Kb2-c3 37.Db5-g5












Code: Select all

Smaug32:
   2	00:00	          97	0	+8,62	24.Kg7-f6 c3-c2 25.Kf6-e5
   2	00:00	         483	0	+8,68	24.Db7-h1+ Kc1-b2 25.Kg7-f6
   3	00:00	       1.338	0	+8,92	24.Db7-h1+ Kc1-b2 25.Dh1-b7+ Kb2-c1 26.Kg7-f6
   4	00:00	       2.647	85.387	+8,62	24.Db7-h1+ Kc1-b2 25.Dh1-b7+ Kb2-c1 26.Kg7-f6 c3-c2 27.Kf6-e5
   5	00:00	       9.272	299.096	+7,50	24.Db7-h1+ Kc1-b2 25.Dh1-b7+ Kb2-c1 26.Kg7-f6 c3-c2 27.Kf6-e5 Kc1-d2 28.Db7-d5+ Kd2-e3
   5	00:00	      16.170	351.521	+8,11	24.Db7-d5 c3-c2 25.Kg7-f6 Kc1-b2 26.Dd5-b5+ Kb2-a1 27.Db5-c4
   6	00:00	      26.273	571.152	+7,15	24.Db7-d5 c3-c2 25.Kg7-f6 Kc1-b2 26.Dd5-b5+ Kb2-a1 27.Db5-c4 Ka1-b2 28.Dc4-b4+ Kb2-a2
   6	00:00	      31.653	290.394	+7,54	24.Db7-h1+ Kc1-b2 25.Dh1-b7+ Kb2-c1 26.Kg7-f6 c3-c2 27.Kf6-e5 Kc1-d2 28.Db7-d5+ Kd2-e2
   6	00:00	      50.475	269.919	+7,90	24.Kg7-g6 c3-c2 25.Kg6-f5 Kc1-d2 26.Db7-d5+ Kd2-c3 27.Dd5-a5+ Kc3-b2 28.Da5-b4+ Kb2-a2
   6	00:00	      60.090	321.336	+8,11	24.Kg7-f6 c3-c2 25.Db7-h1+ Kc1-b2 26.Dh1-b7+ Kb2-c3 27.Db7-c7+ Kc3-b2 28.Dc7-b6+ Kb2-a1 29.Db6-e3
   7	00:00	      68.442	337.152	+8,11	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-d5+ Kd2-e2 27.Dd5-c4+ Ke2-d2 28.Dc4-d4+ Kd2-e2 29.Dd4-f4
   8	00:00	      85.155	303.042	+8,66	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-d5+ Kd2-e2 27.Dd5-c4+ Ke2-d2 28.Dc4-d4+ Kd2-c1 29.Ke5-e4 Kc1-b1 30.Dd4-b4+ Kb1-a2
   9	00:00	     106.772	311.288	+8,66	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-d5+ Kd2-e2 27.Dd5-c4+ Ke2-d2 28.Dc4-d4+ Kd2-c1 29.Ke5-e4 Kc1-b1 30.Dd4-b4+ Kb1-a2
  10	00:00	     135.428	361.141	+9,31	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-d5+ Kd2-e2 27.Dd5-c4+ Ke2-d2 28.Dc4-d4+ Kd2-c1 29.Ke5-e4 Kc1-b1 30.Dd4-b4+ Kb1-a2 31.Db4-c5
  11	00:00	     161.244	368.979	+9,37	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-d5+ Kd2-e2 27.Dd5-c4+ Ke2-d2 28.Dc4-d4+ Kd2-c1 29.Ke5-e4 Kc1-b1 30.Dd4-b4+ Kb1-a2 31.Db4-c3 Ka2-b1 32.Dc3-b3+ Kb1-c1
  12	00:00	     193.425	354.258	+9,37	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-d5+ Kd2-e2 27.Dd5-c4+ Ke2-d2 28.Dc4-d4+ Kd2-c1 29.Ke5-e4 Kc1-b1 30.Dd4-b4+ Kb1-a2 31.Db4-c3 Ka2-b1 32.Dc3-b3+ Kb1-c1
  13	00:00	     276.452	361.375	+9,74	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-d5+ Kd2-e2 27.Dd5-c4+ Ke2-d2 28.Dc4-d4+ Kd2-c1 29.Ke5-e4 Kc1-b1 30.Dd4-b4+ Kb1-a2 31.Db4-c3 Ka2-b1 32.Dc3-b3+ Kb1-c1 33.Ke4-d3
  14	00:01	     475.206	375.656	+9,27	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Dd4-d3 Kc1-b2 29.Dd3-d2 Kb2-b1 30.Dd2-b4+ Kb1-a2 31.Db4-c3 Ka2-b1 32.Dc3-b3+ Kb1-c1 33.Ke5-d4
  15	00:03	   1.131.350	385.205	+9,47	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Dd4-d3 Kc1-b2 29.Dd3-d2 Kb2-b1 30.Dd2-b4+ Kb1-a2 31.Db4-c3 Ka2-b1 32.Dc3-b3+ Kb1-c1 33.Ke5-d4 Kc1-d2 34.Db3-d3+ Kd2-c1
  16	00:04	   1.894.099	410.956	+9,47	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Dd4-d3 Kc1-b2 29.Dd3-d2 Kb2-b1 30.Dd2-b4+ Kb1-a2 31.Db4-c3 Ka2-b1 32.Dc3-b3+ Kb1-c1 33.Ke5-d4 Kc1-d2 34.Db3-d3+ Kd2-c1
  17	00:11	   4.629.384	419.100	+9,84	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Dd4-d3 Kc1-b2 29.Dd3-d2 Kb2-b1 30.Dd2-b4+ Kb1-a2 31.Db4-c3 Ka2-b1 32.Dc3-b3+ Kb1-c1 33.Ke5-d4 Kc1-d2 34.Db3-d3+ Kd2-c1 35.Kd4-e3
  18	00:28	  12.279.210	425.033	+9,27	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Ke5-e4 Kc1-b1 29.Dd4-b4+ Kb1-a2 30.Db4-c3 Ka2-b1 31.Dc3-b3+ Kb1-a1 32.Db3-e3 Ka1-b2 33.De3-b6+ Kb2-a2 34.Db6-a7+ Ka2-b2 35.Da7-g7+ Kb2-b1 36.Dg7-b7+ Kb1-a2 37.Db7-c6

Code: Select all

Stockfish-163-32-ja:
   1	00:00	          37	45	+9,25	24.Kg7-f6
   2	00:00	         162	199	+8,96	24.Kg7-f6 c3-c2 25.Kf6-e5
   3	00:00	         672	826	+7,91	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-d5+ Kd2-e3
   3	00:00	       1.222	1.503	+9,13	24.Db7-h1+ Kc1-b2 25.Dh1-b7+ Kb2-c1 26.Kg7-g6 c3-c2
   4	00:00	       1.837	2.259	+8,16	24.Db7-h1+ Kc1-b2 25.Dh1-b7+ Kb2-c1 26.Kg7-g6 c3-c2 27.Db7-d5
   5	00:00	       3.806	4.681	+7,75	24.Db7-h1+ Kc1-b2 25.Dh1-b7+ Kb2-c1 26.Kg7-g6 c3-c2 27.Kg6-f5 Kc1-d2 28.Db7-d5+ Kd2-e3
   5	00:00	       6.318	7.771	+8,20	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-d5+ Kd2-c3 27.Dd5-d4+ Kc3-b3
   6	00:00	       9.451	11.414	+7,95	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-d5+ Kd2-e1 27.Dd5-c4 Ke1-d2 28.Dc4-d4+ Kd2-e2
   7+	00:00	      14.167	17.109	+8,48	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-e2 28.Dd4-c3
   8	00:00	      23.926	28.896	+9,09	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-c1 28.Dd4-c3 Kc1-b1 29.Dc3-b4+ Kb1-a2 30.Db4-c5
   9	00:01	      51.743	56.120	+9,01	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-e1 28.Dd4-c3+ Ke1-d1 29.Dc3-d3+ Kd1-c1 30.Ke5-e4 Kc1-b2 31.Dd3-d4+ Kb2-b1 32.Dd4-b4+ Kb1-a2 33.Db4-c3 Ka2-b1 34.Dc3-b3+ Kb1-c1
  10+	00:01	      69.977	69.977	+9,25	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-e1 28.Dd4-c3+ Ke1-d1 29.Dc3-d3+ Kd1-c1 30.Ke5-e4 Kc1-b2 31.Dd3-d4+ Kb2-b1 32.Dd4-b4+ Kb1-a2 33.Db4-c3 Ka2-b1 34.Dc3-b3+ Kb1-c1
  11	00:01	     115.650	107.282	+10,10	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-e1 28.Dd4-c3+ Ke1-d1 29.Dc3-d3+ Kd1-c1 30.Ke5-d4 Kc1-b2 31.Dd3-c3+ Kb2-b1 32.Dc3-b3+ Kb1-c1 33.Kd4-e3
  12+	00:01	     189.290	145.944	+11,79	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-e1 28.Dd4-c3+ Ke1-d1 29.Dc3-d3+ Kd1-c1 30.Ke5-e4 Kc1-b2 31.Dd3-d4+ Kb2-c1 32.Ke4-d3
  13+	00:01	     202.028	155.765	+85,22	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-e1 28.Dd4-c3+ Ke1-d1 29.Dc3-d3+ Kd1-c1 30.Ke5-e4 Kc1-b2 31.Dd3-d4+ Kb2-c1 32.Ke4-d3
  14	00:02	     530.173	271.465	+10,10	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-e1 28.Dd4-e3+ Ke1-d1 29.De3-d3+ Kd1-c1 30.Ke5-e4 Kc1-b2 31.Dd3-d4+ Kb2-b1 32.Dd4-b4+ Kb1-a2 33.Db4-c3 Ka2-b1 34.Dc3-b3+ Kb1-c1 35.Ke4-e3 Kc1-d1 36.Db3-d5+ Kd1-c1
  15	00:04	   1.900.774	431.405	+10,30	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-e1 28.Dd4-e3+ Ke1-d1 29.De3-d3+ Kd1-c1 30.Ke5-e4 Kc1-b2 31.Dd3-d4+ Kb2-b1 32.Dd4-b4+ Kb1-a2 33.Db4-a5+ Ka2-b2 34.Da5-b6+ Kb2-a2 35.Db6-g1 Ka2-b3 36.Dg1-c1 Kb3-c3 37.Ke4-e3
  16	00:08	   4.444.059	521.848	+9,61	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-d4+ Kd1-e1 28.Dd4-e3+ Ke1-d1 29.De3-d3+ Kd1-c1 30.Ke5-e4 Kc1-b2 31.Dd3-d4+ Kb2-b1 32.Dd4-b4+ Kb1-a2 33.Db4-a5+ Ka2-b2 34.Da5-b6+ Kb2-a2 35.Db6-g1 Ka2-b2 36.Dg1-h2 Kb2-b1 37.Dh2-b8+ Kb1-a2 38.Db8-a7+ Ka2-b1 39.Da7-b7+ Kb1-a2 40.Db7-c6 Ka2-b2 41.Dc6-b6+
  16	00:14	   7.534.353	520.148	+89,24	24.Kg7-f7 Kc1-d2 25.Db7-d5+ Kd2-c2 26.Kf7-f6 Kc2-b2 27.Dd5-d4 Kb2-b3 28.Kf6-e5 c3-c2 29.Dd4-a1 Kb3-c4 30.Da1-a3 Kc4-b5 31.Da3-b2+ Kb5-a6 32.Db2xc2 Ka6-b5 33.Ke5-d4 Kb5-b6 34.Dc2-c4 Kb6-b7 35.Kd4-c5 Kb7-c7
  17	00:24	  13.686.456	560.048	+89,19	24.Kg7-f7 c3-c2 25.Kf7-f6 Kc1-d1 26.Db7-d5+ Kd1-e1 27.Dd5-e4+ Ke1-d2 28.De4-b4+ Kd2-d1 29.Db4-d4+ Kd1-e2 30.Dd4-c3 Ke2-d1 31.Dc3-d3+ Kd1-c1 32.Kf6-f5 Kc1-b2 33.Dd3-d2 Kb2-b1 34.Dd2-b4+ Kb1-a1 35.Db4-c3+ Ka1-b1 36.Dc3-b3+ Kb1-a1 37.Db3xc2
  18	00:28	  16.474.158	585.747	+89,19	24.Kg7-f7 c3-c2 25.Kf7-f6 Kc1-d1 26.Db7-d5+ Kd1-e1 27.Dd5-e4+ Ke1-d2 28.De4-b4+ Kd2-d1 29.Db4-d4+ Kd1-e2 30.Dd4-c3 Ke2-d1 31.Dc3-d3+ Kd1-c1 32.Kf6-f5 Kc1-b2 33.Dd3-d2 Kb2-b1 34.Dd2-b4+ Kb1-a1 35.Db4-c3+ Ka1-b1 36.Dc3-b3+ Kb1-a1 37.Db3xc2
  19	00:33	  20.316.748	605.620	+89,19	24.Kg7-f7 c3-c2 25.Kf7-f6 Kc1-d1 26.Db7-d5+ Kd1-e1 27.Dd5-e4+ Ke1-d2 28.De4-b4+ Kd2-d1 29.Db4-d4+ Kd1-e2 30.Dd4-c4+ Ke2-d1 31.Dc4-d3+ Kd1-c1 32.Dd3-b3 Kc1-d1 33.Kf6-f5 Kd1-d2 34.Db3-b2 Kd2-d1 35.Db2-d4+ Kd1-e2 36.Dd4-c3 Ke2-d1 37.Dc3-d3+ Kd1-c1 38.Dd3-d6 Kc1-b1 39.Dd6-b4+ Kb1-a1 40.Db4-c3+ Ka1-b1 41.Dc3-b3+ Kb1-a1 42.Db3xc2
  20	00:38	  23.812.173	626.372	+89,19	24.Kg7-f7 c3-c2 25.Kf7-f6 Kc1-d1 26.Db7-d5+ Kd1-e1 27.Dd5-e4+ Ke1-d2 28.De4-b4+ Kd2-d1 29.Db4-d4+ Kd1-e2 30.Dd4-c4+ Ke2-d1 31.Dc4-d3+ Kd1-c1 32.Dd3-b3 Kc1-d1 33.Kf6-f5 Kd1-d2 34.Db3-a2 Kd2-c3 35.Da2-a5+ Kc3-b2 36.Da5-b4+ Kb2-a1 37.Db4-c3+ Ka1-b1 38.Dc3-b3+ Kb1-a1 39.Db3xc2
  20	00:42	  26.859.512	631.750	+89,24	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-a4 Kd1-d2 28.Da4-d4+ Kd2-e2 29.Dd4-a1 Ke2-d2 30.Da1-a5+ Kd2-e2 31.Da5-c5 Ke2-d1 32.Dc5-g1+ Kd1-d2 33.Dg1-f2+ Kd2-d1 34.Df2-f1+ Kd1-d2 35.Df1-f4+ Kd2-e2 36.Ke5-d4 Ke2-d1 37.Df4-f1+ Kd1-d2 38.Df1-d3+ Kd2-e1 39.Dd3xc2 Ke1-f1 40.Dc2-h2 Kf1-e1 41.Kd4-e3
  21	00:47	  30.742.981	645.942	+89,24	24.Kg7-f6 c3-c2 25.Kf6-e5 Kc1-d2 26.Db7-b4+ Kd2-d1 27.Db4-a4 Kd1-d2 28.Da4-d4+ Kd2-e2 29.Dd4-a1 Ke2-d2 30.Da1-a5+ Kd2-e2 31.Da5-c5 Ke2-d1 32.Dc5-g1+ Kd1-d2 33.Dg1-f2+ Kd2-d1 34.Df2-f1+ Kd1-d2 35.Df1-f4+ Kd2-e2 36.Ke5-d4 Ke2-d1 37.Df4-f1+ Kd1-d2 38.Df1-d3+ Kd2-e1 39.Dd3xc2 Ke1-f1 40.Dc2-h2 Kf1-e1 41.Kd4-e3
...

Michael
http://www.playwitharena.com
Top
BBauer
Posts: 658
Joined: Wed Mar 08, 2006 8:58 pm

Re: Stockfish endgame weakness

Post by BBauer »

FEN: 8/1Q4K1/8/8/8/2p5/8/2k5 w - - 0 24

Critter_0.70_64bit:
2/1 00:00 0 0 0,00 Kg7f6
Why do you wonder ?
1. Because critter seas it in zero seconds.
2. Because there is a position I can do better than stockfish et al.

kind regards
Bernhard
Top
Tord Romstad
Posts: 1808
Joined: Wed Mar 08, 2006 9:19 pm
Location: Oslo, Norway

Re: Stockfish endgame weakness

Post by Tord Romstad »

BBauer wrote:2 mb is not much today. That would resolve the KQKP problem in general.
Actually, 2 MB is a lot today. Arguably, it's a lot more than it was a few years ago. This is because 99% of all users run the program on an iPhone, where memory is a scarce resource. For this reason, bitbases and tablebases are very unsatisfactory replacements for basic endgame knowledge.

Stockfish has knowledge about several types of basic endgames, but as you have just discovered yourself, this particular endgame has still not been added. We'll probably add it some time, and your post makes it a little more likely that it will happen soon. Thanks for reminding us. :-)

As has been pointed out elsewhere in the thread, there also appears to be a search bug here.
Top

Return to “Computer Chess Club: General Topics”