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Subject: Re: Crafty bug? (18.12)

Author: Dann Corbit

Date: 11:20:39 10/18/01

Go up one level in this thread


On October 18, 2001 at 10:47:50, Rafael Andrist wrote:

>On October 18, 2001 at 08:51:56, Robert Hyatt wrote:
>
>>On October 17, 2001 at 17:49:39, Robert Hyatt wrote:
>>
>>>On October 17, 2001 at 13:05:35, Roy Eassa wrote:
>>>
>>>>On October 17, 2001 at 13:02:34, Robert Hyatt wrote:
>>>>
>>>>>On October 17, 2001 at 11:15:12, Robert Hyatt wrote:
>>>>>
>>>>>>definitely a bug of some sort...
>>>>>
>>>>>A pretty simple bug in fact.  I just fixed it in the 18.12 source and
>>>>>re-copied the source to the ftp machine.  If you want to try the fix,
>>>>>feel free.  There was a bad calculation that failed when the king was within
>>>>>one square of the rook-file promotion square, and the pawn was within one square
>>>>>of the promotion square, and the pawn was to move first...
>>>>
>>>>
>>>>Was the bug only in 18.12, or was it also in previous versions?
>>>
>>>
>>>Been there a while...  Nothing has been changed here for several versions.  I
>>>am completely rewriting the EvaluateDraws() code and have changed the name to
>>>EvaluateWinner().  It returns a bitmask of two bits, 01 means white can win
>>>only, 10 means black can win only, 11 means either can win, and 00 means dead
>>>drawn.
>>>
>>>It also recognizes a few more cases.  I temporarily deleted the 18.12 source
>>>as I want to fix this completely as part of the final 18.12 release.  I hope to
>>>finish it tonight...
>>
>>
>>New version is now available.  It at least handles the test position for this
>>thread correctly.  The search is more "stable" in the endgame as well, now.
>
>Did you include this KBP-KP case or did you only fix the bug in the evaluation
>of KBP-K endgames? Do you also handle cases, where the defending king is near
>enough, but can be forced to go away? E.g.
>
>[D]5k2/8/3K3P/8/8/8/2B5/8 w - - 0 1

EPD Kit revision date: 1996.04.21
unable to open book file [e:\crafty\release/books.bin].
hash table memory = 192M bytes.
pawn hash table memory = 80M bytes.
EGTB cache memory = 32M bytes.
draw score set to    0.00 pawns.
choose from book moves randomly (using weights.)
choose from 5 best moves.
book learning enabled
result learning enabled
position learning enabled
threshold set to 9 pawns.
5 piece tablebase files found
19045kb of RAM used for TB indices and decompression tables

Crafty v18.12

White(1): st 60
search time set to 60.00.
White(1): setboard 5k2/8/3K3P/8/8/8/2B5/8 w - -
1. Bb3 Ke8 2. h7 Kd8 3. h8=Q#
White(1):



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