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

Author: Robert Hyatt

Date: 21:23:42 01/14/98

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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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