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Subject: Re: Null move question

Author: Rick Bischoff

Date: 14:18:12 07/30/03

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>>
>>a. at depth 3- hash table is empty for this position.  alpha = -INF, beta = +INF
>>a. all requirements for null move are met
>>a. makes null move:  int e = -alphabeta(depth - 3, -beta, -beta +1);
>>
>>b. now we are at depth 0, alpha = -INF, beta = -INF + 1
>>b. we call quies(alpha, beta)
>>
>>c.  e = static eval is, oh say, 1.
>>c.  e >= beta, return beta
>>
>>b. store this position in the hash table as -INF + 1, exact, depth = 0, return
>>-INF + 1
>
>This is _way_ wrong.  How can it be "exact"???  It is impossible for the
>search to return valid scores outside alpha/beta window as defined at the
>root.  If you are returning an "edge" then it must be an upper or lower
>edge, not an exact score.

Yes, I know it is wrong-- which is why I was asking the question to begin with
:-) What I do know is store anything quies returns as exact-- but you are
telling me I can't do that, right?  (Forgive my ignorance!)




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