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Subject: KB*KP* -> some first promising results

Author: Thomas Mayer

Date: 13:44:48 02/01/05


Hi,

I had promised some more interesting results of my experiments with
KB*KP* endgames... The following analysis are produced by an alpha
version of Quark after implementing KBKP bitbase, a recognizer and
a special endgame routine for KB*KP* endgames. 5-men tablebases are
disabled.
The implementation has definitely NO influence at all to Quarks
overall speed.

[D] 8/p1p5/3p4/p3p3/k4p2/2K3pB/7p/8 w - - 0 1

A well known position, the lone bishop holds against 8 pawns... I
do not know any engine which can even nearly analyse this correct
in a reasonable amount of time. (Maybe Yace can, Dieter is a clever
guy, I have not tested... :)
Let's have a look what Quark v2.47alpha thinks on this:

Quark v2.47alpha:
  12	00:00	     123.374	560.790	-1,66	h3d7 a4a3 d7c6 a5a4 c6h1 a7a5 h1d5 h2h1q
d5h1 c7c5 INRHits:2515
  12	00:00	     141.585	566.340	-1,66	h3d7 a4a3 d7c6 a5a4 c6h1 a7a5 h1d5 h2h1q
d5h1 c7c5 INRHits:3532
  13	00:00	     244.659	556.043	-1,68	h3d7 a4a3 d7c6 a5a4 c6h1 a7a5 h1d5 h2h1q
d5h1 c7c6 h1c6 a3a2 c3c4 a4a3 INRHits:5178
  13	00:00	     276.458	564.200	-1,68	h3d7 a4a3 d7c6 a5a4 c6h1 a7a5 h1d5 h2h1q
d5h1 c7c6 h1c6 a3a2 c3c4 a4a3 INRHits:6777
  14	00:00	     376.445	579.146	-1,68	h3d7 a4a3 d7c6 a5a4 c6h1 a7a5 h1d5 c7c6
d5c6 a3a2 c6d5 a2b1 d5g2 h2h1q g2h1 a4a3 INRHits:8633
  14	00:01	     435.167	572.588	-1,68	h3d7 a4a3 d7c6 a5a4 c6h1 a7a5 h1d5 c7c6
d5c6 a3a2 c6d5 a2b1 d5g2 h2h1q g2h1 a4a3 INRHits:11399
  15	00:01	     692.298	581.763	-1,67	h3d7 a4a3 d7c6 a5a4 c6h1 a7a5 h1d5 c7c6
d5c6 a3a2 c6d5 a2b1 d5e4 b1c1 e4h1 c1d1 h1f3 d1e1 c3c4 INRHits:17585
  15	00:01	     808.902	581.943	-1,67	h3d7 a4a3 d7c6 a5a4 c6h1 a7a5 h1d5 c7c6
d5c6 a3a2 c6d5 a2b1 d5e4 b1c1 e4h1 c1d1 h1f3 d1e1 c3c4 INRHits:21942
  16	00:02	   1.124.098	588.532	-1,68	h3d7 a4a3 d7c6 a5a4 c6h1 a7a5 h1d5 c7c6
d5c6 a3a2 c6d5 a2b1 d5e4 b1c1 e4h1 c1d1 c3d3 a4a3 d3e4 INRHits:29444
  16	00:02	   1.358.386	593.181	-1,68	h3d7 a4a3 d7c6 a5a4 c6h1 a7a5 h1d5 c7c6
d5c6 a3a2 c6d5 a2b1 d5e4 b1c1 e4h1 c1d1 c3d3 a4a3 d3e4 INRHits:37674
  17	00:03	   2.151.581	599.326	-1,98	h3d7?
  17	00:05	   4.064.056	692.343	-2,21	h3d7 a4a3 d7c6 a5a4 c6d5 a7a5 c3c2 h2h1q
d5h1 a3a2 h1d5 a2a1 d5c6 a4a3 c2b3 a3a2 b3a3 e5e4 c6e4 c7c5 g2e4 INRHits:62874
  17	00:07	   5.256.508	667.069	-2,20	h3g2!
  17	00:22	  14.434.963	637.305	-2,21	h3d7 a4a3 d7c6 a5a4 c6d5 a7a5 c3c2 h2h1q
d5h1 a3a2 h1d5 a2a1 d5c6 a4a3 c2b3 a3a2 b3a3 e5e4 c6e4 c7c5 g2e4 INRHits:305950
  17	00:22	  14.479.187	639.257	-2,21	h3d7 a4a3 d7c6 a5a4 c6d5 a7a5 c3c2 h2h1q
d5h1 a3a2 h1d5 a2a1 d5c6 a4a3 c2b3 a3a2 b3a3 e5e4 c6e4 c7c5 g2e4 INRHits:308271
  18	00:23	  15.147.797	633.799	-2,22	h3d7 a4a3 d7c6 a5a4 c6d5 a7a5 c3c2 h2h1q
d5h1 a3a2 h1d5 a2a1 d5c6 a4a3 c2b3 d6d5 c6d5 c7c6 d5c6 a3a2 INRHits:326694
  18	00:24	  15.514.814	635.853	-2,22	h3d7 a4a3 d7c6 a5a4 c6d5 a7a5 c3c2 h2h1q
d5h1 a3a2 h1d5 a2a1 d5c6 a4a3 c2b3 d6d5 c6d5 c7c6 d5c6 a3a2 INRHits:352358
  19	00:26	  17.143.833	643.295	-2,20	h3d7 a4a3 d7c6 a5a4 c6d5 a7a5 c3c2 h2h1q
d5h1 a3a2 h1d5 a2a1 d5c6 a4a3 c2b3 d6d5 c6d5 c7c6 d5c6 a3a2 b3c4 INRHits:381154
  19	00:27	  17.752.277	641.803	-2,20	h3d7 a4a3 d7c6 a5a4 c6d5 a7a5 c3c2 h2h1q
d5h1 a3a2 h1d5 a2a1 d5c6 a4a3 c2b3 d6d5 c6d5 c7c6 d5c6 a3a2 b3c4 INRHits:417484
  20	00:32	  21.168.482	648.147	-2,22	h3d7 a4a3 d7c6 a5a4 c6d5 a7a5 c3c2 h2h1q
d5h1 a3a2 h1d5 a2a1 d5c6 a4a3 c2c3 a3a2 c3b3 d6d5 c6d5 c7c5 d5c6 a1b1 c6e4 a5a4
INRHits:593733
  20	00:33	  21.900.935	663.664	-2,22	h3d7 a4a3 d7c6 a5a4 c6d5 a7a5 c3c2 h2h1q
d5h1 a3a2 h1d5 a2a1 d5c6 a4a3 c2c3 a3a2 c3b3 d6d5 c6d5 c7c5 d5c6 a1b1 c6e4 a5a4
INRHits:638178
  21	00:40	  27.154.040	678.851	-2,24	h3d7 a4a3 d7c6 a5a4 c6d5 a7a5 c3c2 h2h1q
d5h1 a3a2 h1d5 a2a1 d5c6 a4a3 c2b3 a3a2 b3a3 a5a4 c6d5 c7c5 d5g2 c5c4 g2e4
INRHits:713966
  21	00:42	  28.346.752	674.922	-2,24	h3d7 a4a3 d7c6 a5a4 c6d5 a7a5 c3c2 h2h1q
d5h1 a3a2 h1d5 a2a1 d5c6 a4a3 c2b3 a3a2 b3a3 a5a4 c6d5 c7c5 d5g2 c5c4 g2e4
INRHits:791005

of course this is not perfect, but sufficent, I think... In the line
you see, that Quark did understand it. I believe that other engines will
produce similar lines, but I have doubts that they score it near to that.
You are welcome to test this with some engines...

Let's go a bit deeper in the endgame:

[Event "Computer Schach Partie"]
[Site "SHITHAPPENS"]
[Date "2005.02.01"]
[Round "?"]
[White "Thomas"]
[Black "Thomas"]
[Result "*"]
[BlackElo "2350"]
[Time "22:33:40"]
[WhiteElo "2350"]
[SetUp "1"]
[FEN "8/p1p5/3p4/p3p3/k4p2/2K3pB/7p/8 w - - 0 1 "]
[Termination "unterminated"]
[PlyCount "17"]
[WhiteType "human"]
[BlackType "human"]

1.Bd7+ Ka3 2.Bc6 a4 3.Bd5 c5 4.Bg2 Ka2 5.Kc2 a5 6.Bh1 Ka1 7.Bg2 a3 8.Bh1 a2
9.*

So we get this position:

[D] 8/8/3p4/p1p1p3/5p2/6p1/p1K4p/k6B w - - 0 9

Quarks analysis (besides, all on my P3/1200 Laptop
Of course I have reseted Quarks hashtables

   5	00:00	       2.498	249.800	-2,32	h1e4 a5a4 c2c3 a4a3 c3d3 INRHits:10
   7	00:00	      12.132	404.400	-2,34	h1d5 a5a4 d5e4 a4a3 c2c3 d6d5 e4d5 a4a3
INRHits:101
   8	00:00	      25.180	419.666	-2,27	h1e4 a5a4 e4d5 c5c4 c2c1 e5e4 d5e4 a4a3
INRHits:328
  11	00:00	     113.926	542.504	-2,26	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1d5 e5e4
d5e4 d6d5 e4d5 INRHits:2129
  12	00:00	     134.248	559.366	-2,26	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
c2c3 d6d5 e4d5 a1b1 INRHits:2725
  12	00:00	     155.532	555.471	-2,26	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
c2c3 d6d5 e4d5 a1b1 INRHits:3117
  13	00:00	     180.650	547.424	-2,28	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 e5e4 d5e4 INRHits:3952
  13	00:00	     212.275	558.618	-2,28	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 e5e4 d5e4 INRHits:4930
  14	00:00	     274.342	548.684	-2,15	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 e5e4 d5e4 f4f3 g2f3 INRHits:6655
  14	00:00	     300.106	555.751	-2,15	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 e5e4 d5e4 f4f3 g2f3 INRHits:7481
  15	00:01	     365.359	562.090	-2,15	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 e5e4 d5e4 f4f3 e4f3 INRHits:9785
  15	00:01	     405.765	555.842	-2,15	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 e5e4 d5e4 f4f3 e4f3 INRHits:11146
  16	00:01	     557.760	557.760	-2,00	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 e5e4 d5e4 f4f3 e4f3 g3g2 INRHits:16118
  16	00:01	     620.571	559.072	-2,00	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 e5e4 d5e4 f4f3 e4f3 g3g2 INRHits:18419
  17	00:01	     832.700	555.133	-1,65	h1e4!
  17	00:02	     995.954	559.524	-1,38	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 h2h1q d5h1 f4f3 h1f3 e5e4 f3e4 INRHits:30032
  17	00:02	   1.091.918	559.957	-1,38	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 h2h1q d5h1 f4f3 h1f3 e5e4 f3e4 INRHits:33185
  18	00:03	   2.059.706	567.412	-1,23	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 h2h1q d5h1 f4f3 h1f3 e5e4 f3e4 g3g2 INRHits:65938
  18	00:04	   2.204.087	518.608	-1,23	h1e4 a5a4 e4d5 c5c4 d5h1 a4a3 h1e4 c4c3
e4h1 d6d5 h1d5 h2h1q d5h1 f4f3 h1f3 e5e4 f3e4 g3g2 INRHits:73115
  19	00:05	   2.907.600	553.828	-0,78	h1e4!
  19	00:06	   3.520.072	563.211	 0,00	h1e4 h2h1q e4h1 e5e4 h1e4 c5c4 e4h1 d6d5
h1d5 g3g2 d5g2 f4f3 g2f3 c4c3 f3h1 a5a4 h1g2 a4a3 g2h1 INRHits:107151
  19	00:06	   3.858.276	570.750	 0,00	h1e4 h2h1q e4h1 e5e4 h1e4 c5c4 e4h1 d6d5
h1d5 g3g2 d5g2 f4f3 g2f3 c4c3 f3h1 a5a4 h1g2 a4a3 g2h1 INRHits:118274
  20	00:09	   5.094.121	565.385	 0,00	h1e4 h2h1q e4h1 e5e4 h1e4 c5c4 e4h1 d6d5
h1d5 g3g2 d5g2 f4f3 g2f3 c4c3 f3h1 a5a4 h1g2 a4a3 g2h1 INRHits:153665
  20	00:09	   5.526.742	566.264	 0,00	h1e4 h2h1q e4h1 e5e4 h1e4 c5c4 e4h1 d6d5
h1d5 g3g2 d5g2 f4f3 g2f3 c4c3 f3h1 a5a4 h1g2 a4a3 g2h1 INRHits:171991
  21	00:10	   5.911.715	576.190	 0,00	h1e4 h2h1q e4h1 e5e4 h1e4 c5c4 e4h1 d6d5
h1d5 g3g2 d5g2 f4f3 g2f3 c4c3 f3h1 a5a4 h1g2 a4a3 g2h1 INRHits:183063
  21	00:11	   6.500.600	577.317	 0,00	h1e4 h2h1q e4h1 e5e4 h1e4 c5c4 e4h1 d6d5
h1d5 g3g2 d5g2 f4f3 g2f3 c4c3 f3h1 a5a4 h1g2 a4a3 g2h1 INRHits:211417
  22	00:12	   7.104.087	579.452	 0,00	h1e4 h2h1q e4h1 e5e4 h1e4 c5c4 e4h1 d6d5
h1d5 g3g2 d5g2 f4f3 g2f3 c4c3 f3h1 a5a4 h1g2 a4a3 g2h1 INRHits:229468
  22	00:13	   7.928.700	586.442	 0,00	h1e4 h2h1q e4h1 e5e4 h1e4 c5c4 e4h1 d6d5
h1d5 g3g2 d5g2 f4f3 g2f3 c4c3 f3h1 a5a4 h1g2 a4a3 g2h1 INRHits:274146

It does really work...
Well, Vincent might be right -> anyway, I think the nearly understanding
of such positions MUST have some influence on it's endgame strength, I
will continue to work on this...

Greets, Thomas



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