Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Endgame position

Author: Uri Blass

Date: 12:06:21 07/29/03

Go up one level in this thread


On July 29, 2003 at 14:19:37, Gerd Isenberg wrote:

>On July 29, 2003 at 12:11:21, Ulrich Tuerke wrote:
>
>>On July 29, 2003 at 11:59:06, Ulrich Tuerke wrote:
>>
>>>On July 29, 2003 at 11:56:12, Steffen Jakob wrote:
>>>
>>>>Hi Uli!
>>>>
>>>>On July 29, 2003 at 11:50:14, Ulrich Tuerke wrote:
>>>>
>>>>>>[D]8/p7/2K5/1P6/1k6/8/7p/7B w - - 0 67
>>>>>>
>>>>>>Is there an engine which sees that this is a draw? Here is the complete score:
>>>>
>>>>>Comet sees it (without TB); I guess, many engines will:
>>>>
>>>>At least Hossa and Fritz 8 don't.
>>>>
>>>>>Comet-B.60    Tue Jul 29 17:43:34 2003
>>>>>
>>>>>depth	score	  sec	  nodes		  pv
>>>>> 1.	-0.98	    0	       37	 h1e4
>>>>> 2.	-0.98	    0	      118	 h1d5  b4c3
>>>>> 3.	-0.84	    0	      594	 h1d5  b4c3  c6d6
>>>>> 4.	-0.40	    0	      991	 h1d5  b4c3  d5h1  c3d4
>>>>> 4.	-0.40	    0	     1750	 h1d5  b4c3  d5h1  c3d4
>>>>> 5.	-0.67	    0	     4167	 h1d5  b4a5  c6c5  a5a4  d5b7
>>>>> 5.	-0.67	    0	     7274	 h1d5  b4a5  c6c5  a5a4  d5b7
>>>>> 6.	-0.29	    0	    10668	 h1d5  b4c3  c6d6  c3d4  d5c6  d4e3
>>>>> 6.	-0.29	    0	    20066	 h1d5  b4c3  c6d6  c3d4  d5c6  d4e3
>>>>> 7.	-0.08	    0	    43767	 h1d5  b4a4  d5e4  a4a5  c6c5  a7a6  b5b6
>>>>
>>>>Do I interpret this correctly that Comet sees an advantage for black in the
>>>>first 7 plies? Bishop and pawn vs. 2 bishops?
>>>
>>>Yes, that's right.
>>>What have I done ?
>>>
>>>I guess, I'll have to have a look into the code to understand.  -:)
>>
>>
>>
>>Looks like, it's black advanced passer leading to this score. The value of a
>>lonely bishop decreases in Comet's eval with decreasing number of pawns on the
>>board.
>>
>>OTOH, Comet knows that king + bishop alone can never win. So there is an upper
>>limit of 0.0 for these kind of positions from white's point of view. White can't
>>move its king without loosing it's pawn, which is a draw.
>
>Hi Uli,
>
>really great! Is all that knowledge in static eval for this special ending,
>bishop+pawn against pawns?
>
>Regards,
>Gerd

The knowledge of Comet may be simply wrong and I am not sure if it is productive

Here is an example
Comet can see the win after search but if it is going to be the leaf position it
may be happy with it with black.

New game
[D]8/8/8/1k6/1P6/1K5p/6p1/6B1 w - - 0 1

Analysis by Comet B60:

-+  (-3.80) 1.Bf2   00:00:00
-+  (-3.73) 1.Be3   00:00:00
-+  (-2.75) 1.Bh2   00:00:00
-+  (-2.49) 1.Kc3   00:00:00
-+  (-3.19) 1.Kc3 h2 2.Bxh2 g1Q   00:00:00
-+  (-2.68) 1.Bh2 Kc6   00:00:00
-+  (-2.25) 1.Bh2 Kc6 2.Kc4   00:00:00
-+  (-2.16) 1.Kc3 Kc6 2.Kc4   00:00:00
-+  (-2.58) 1.Kc3 Kc6 2.Bh2 Kb5   00:00:00
-+  (-2.16) 1.Bh2 Kb6 2.Bg1+ Kc6 3.Kc4   00:00:00
-+  (-1.93) 1.Bh2 Kb6 2.Kc4 Kc6 3.b5+ Kb6   00:00:00
-+  (-1.46) 1.Kc3 Kc6 2.Kd3 Kd5 3.b5   00:00:00
-+  (-1.65) 1.Kc3 Kc6 2.Kc4 Kd6 3.b5 Ke5   00:00:00
µ  (-1.18) 1.Kc3 Kc6 2.Kc4 Kc7 3.b5 Kb7 4.Kc5   00:00:00
-+  (-1.48) 1.Kc3 Kc6 2.Kc4 Kb7 3.b5 Ka8 4.Bh2 Kb7   00:00:01
µ  (-1.20) 1.Bh2 Kb6 2.Kc4 Kb7 3.b5 Ka8 4.Kc5 Kb7   00:00:01
µ  (-1.18) 1.Bh2 Kb6 2.Kc4 Kb7 3.b5 Ka7 4.Kc5   00:00:02
µ  (-0.84) 1.Kc3 Kc6 2.Kc4 Kd7 3.b5 Kc8 4.Kd5 h2   00:00:02
µ  (-0.95) 1.Kc3 Kc6 2.Kd3 Kd5 3.b5 Kd6 4.Kc4 Kc7 5.Bh2+   00:00:04
=  (-0.08) 1.Kc3 Kc6 2.Kd4 Kb7 3.Ke4 h2   00:00:06
=  (-0.08) 1.Kc3 Kc6 2.Bh2 Kb6 3.Be5 g1Q 4.Kb3   00:00:06
=  (0.00) 1.Kc3 Kc6 2.Kd4 Kc7 3.Ke3 Kc6 4.Kf3 h2 5.Bxh2 Kb5 6.Kxg2   00:00:10
=  (0.00) 1.Kc3 Kc6 2.Kd4 Kb6 3.Ke4+ Kb5 4.Kf4 h2 5.Bxh2 g1Q 6.Bxg1   00:00:17
±  (0.85) 1.Bh2 Kc6 2.Kc4 Kd7 3.b5 Ke7 4.b6 Kf7 5.b7 Kg6 6.b8Q g1Q   00:00:17
+-  (2.56) 1.Bh2 Kc6 2.Kc4 Kd7 3.b5 Ke7 4.b6 Kf7 5.b7 Kg6 6.b8Q g1R   00:00:17
+-  (3.95) 1.Bh2 Kc6 2.Kc4 Kb7 3.Kc5 Ka7 4.b5 Ka8 5.Kc6 Ka7 6.b6+ Ka6 7.b7 Ka7
8.b8Q+ Ka6 9.Qb6#   00:00:18
+-  (3.91) 1.Bh2 Kc6 2.Kc4 Kb6 3.b5 Ka7 4.Kc5 Kb7   00:00:24

(Blass, Tel-Aviv 29.07.2003)

Uri



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.