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Subject: Re: draw recognition and hash interactions

Author: Rafael Andrist

Date: 09:18:13 07/18/01

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>>The problem happens at the root of the search. I get a hash-cutoff, so no move
>>is investigated and the hash move is returned. This is the code I use:
>>
>>//there's a appropriate hash entry, read the bounds/value:
>>if (iHashPtr->SearchDepth >= RemainingDepth)
>>{
>>	if (iHashPtr->Flag == HashFlagExakt)
>>		return iHashPtr->HashValue; //the returned move is the hash-move
>>	else if (iHashPtr->Flag == HashFlagAlpha && iHashPtr->HashValue > Alpha)
>>		Alpha = iHashPtr->HashValue; //adjust Alpha-Bound
>>	else if (iHashPtr->Flag == HashFlagBeta && iHashPtr->HashValue < Beta)
>>		Beta = iHashPtr->HashValue; //adjust Beta-Bound
>>
>>	if (Alpha >= Beta)
>>		return iHashPtr->HashValue; //the returned move is the hash-move
>>}
>>
>>Please, tell me what is wrong in this code.
>>
>>Rafael B. Andrist
>
>I don't hash at the root because I can't see much reason for it.
>
>I guess, you are doing this in order to get a best move which you try first in
>mover ordering and perhaps you do this to get a reasonable start-window for the
>score.
>This should be no problem. But in any case you should then start your search
>(with iteration nr.1), ignoring depth and score retrieved by the hash probe.
>
>Uli

I'm going to fix it. But ignoring of hash score from previous search only at
iteration 1 at the root or allways?

Thanks
Rafael B. Andrist



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