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Subject: Re: Question: Null Move Fail High and Hash Table

Author: Robert Hyatt

Date: 11:58:37 11/29/99

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On November 29, 1999 at 12:06:57, William Bryant wrote:

>A thought occured to me (which can be a dangerous thing).
>
>When a null move fails high (produces a cutoff), this value is stored in the
>hash table.  Should the depth of the hash table entry be the current depth
>of the search, or the depth used for the Null search (ie depth - null
>reduction).
>
>I have traditionally used depth, and am now testing with a depth - null depth to
>see if it helps/hurts.
>
>I would appreciate comments from others who have tried or considere this.
>
>William
>wbryant@ix.netcom.com


Think about it for a minute.  You just did a null-move R=x search, and it failed
high, so you are fixing to return beta. If you reach this same position again,
at this same depth, shouldn't you do the same thing then?  If you change depth
as you suggest, you won't fail high at this same position should you reach it
again, which seems wrong....



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