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Subject: Re: How many programs can select the 1......h6! drawish move ?

Author: Jarkko Pesonen

Date: 23:39:21 05/06/03

Go up one level in this thread


On May 06, 2003 at 18:36:37, Ricardo Gibert wrote:

>On May 06, 2003 at 08:55:07, Robert Hyatt wrote:
>
>>On May 06, 2003 at 07:05:02, Jarkko Pesonen wrote:
>>
>>>Crafty 19.3 ends up in this position
>>>    white       black
>>>  1  d5          e5
>>>  2  c6+         bxc6
>>>  3  bxc6+       Kc8
>>>  4  d6          e4
>>>  5  Kd4         h5
>>>  6  g4          hxg4
>>>  7  hxg4        f4
>>>  8  Kxe4        ...
>>>
>>>[D]2k5/8/2PP4/6p1/4KpP1/8/8/8 b
>>>
>>> 21->   1:40   6.47   1. ... Kd8 2. Kd4 Kc8 3. Kd3 Kd8 4.
>>>                     Ke4 Kc8 5. Kf3 Kd8 6. Kf2 Kc8 7. Ke2
>>>                     Kd8 8. Kd3 Kc8 9. Kc3 Kd8 10. Kd2 Kc8
>>>                     11. Ke1 f3
>>>
>>>Seems that crafty isn't doing any progress and score is totally wrong(seems to
>>>be draw).
>>>
>>>Is there an easy way to fix this?
>>>Or is this some kind off odd situation that is so rare that it is not
>>>worth fixing?
>>>
>>>Jarkko
>>
>>
>>That can be fixed.  It is the classic problem of two connected passed pawns
>>being valued too high in a king and pawn ending.  If they were separated,
>>white would win easily.  But together, they can be stopped.  I will look
>>at this and fix it.  The code is already there, it just has a hole that I
>>apparently overlooked.
>
>From the diagrammed position:
>
>1...Kd8 2.d7 Ke7 3.Kd4 Kd8 4.Kd5 Ke7
>
>    if 4...Kc7? 5.Ke6 f3 6.Ke7 7.f2 e8=Q+ wins more easily.
>
>5.Kc5 f3 6.Kb6 f2
>
>    if 6...Kd8? 7.Kb7 f2 8.c7+ Kxd7 9.c8=Q+ wins more easily too.
>
>7.Kc7 f1=Q 8.d8=Q+ looks like a win to me.

You mean that the original position wasn't draw after all.
Can you refute moves
    white       black
  1  d5          e5
  2  c6+         bxc6
  3  bxc6+       Kc8
  4  d6          e4
  5  Kd4         h5
  6  g4          hxg4
  7  hxg4        f4
  8  Kxe4        ...




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