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Subject: Re: Endgame position

Author: Ulrich Tuerke

Date: 12:52:36 07/29/03

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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?

Hi Gerd,

I doubt that it's so much knowledge. I guess, it's just by chance that the
poorly tuned eval could "solve" this. It just thinks that black is better; so
white tries a repetition. -:)

Seems that Uri has detected something where it doesn't work.

c/u,
Uli

>
>Regards,
>Gerd
>
>
>>Black can't move its
>>king much either without loosing the game. It has to have a look on white's
>>pawn.
>
>
>>
>>Thus, we see white bishop and black king moving back and forth, leading to
>>repetitions.
>>
>>Uli
>>>
>>>Uli
>>>
>>>
>>>
>>>>
>>>>Greetings,
>>>>Steffen.



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