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Subject: Re: Endgame Tablebases (was Re: Reti Endgame study)

Author: Stuart Cracraft

Date: 07:31:28 01/15/98

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Thanks.

On January 15, 1998 at 00:23:42, Robert Hyatt wrote:

>On January 14, 1998 at 22:20:57, Stuart Cracraft wrote:
>
>>That endgame tablebase search you posted was certainly interesting.
>>Can you digress a little bit about what you did to integrate tablebases
>>in standard play. To the endgame tablebase layperson, it would seem
>>impossible: the files are so large as to not be comfortable in memory
>>and fseeking a disk file during tree search at end points or in the
>>search would be too slow. What's the trick?
>>
>>Also, with maximum tablebases enabled, what do you think is the
>>increase in ratings point strength on ICS?
>>
>>--Stuart
>>
>
>no magic.  I do use fseek() deep in the search tree, but there is one
>trick.  I only probe immediately after a capture.  In fact, I only probe
>after captures that take me to the specific 5 piece files I have, or any
>3-4 piece files.  I probe anywhere depth is > 0, which means *not* in
>the q-search.
>
>It slows down by maybe 50% (worst case) but the scores are 100% correct,
>so the trade-off of speed for accuracy is worth it.
>
>No idea about a rating improvement, but it is obviously better with than
>without.  KRP vs KR has been a big winner or drawer.  KRB vs KR and KRN
>vs
>KR have also been useful since those are pretty common.



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