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

Author: Ricardo Gibert

Date: 15:36:37 05/06/03

Go up one level in this thread


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.




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