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Subject: Re: programming questions

Author: Scott Gasch

Date: 12:01:05 08/24/99

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>It is a terrific help.  First thing you do in Search() should be to probe the
>hash table, as a hit prevents further searching of any kind.  If you find the
>position, but the depth is not sufficient to use, or the bound that was stored
>is not useful, you should still try the 'best move' that was stored in the
>hash entry, before trying any other moves at all, including captures.

So if you get an UPPER or EXACT hit and the depth makes it not useful OR if you
get an UPPER hit and the current alpha < hash value then you should still
proceed to order the best move of the hash table first when you order the
successor moves from this position.

However, if you get a LOWER hit there is no best move -- right?  Since LOWER
hash entries come from prior fail highs I store no best move with these hash
entries.  This makes sense to me because there really is no best move for fail
highs... is this the correct behavior?

Gee, I thought hashing was pretty easy when I first wrote it but now I'm
beginning to see the complexity.

Thanks,
Scott




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