Author: Robert Hyatt
Date: 10:18:36 05/08/04
Go up one level in this thread
On May 08, 2004 at 12:56:24, Jeff GAZET wrote:
>>>>Hi,
>>>>when getting hashtable informations like this :
>>>>switch(target->flags)
>>>> {
>>>> case hashfEXACT: return target->eval; break;
>>>> case hashfALPHA: if(target->eval<=alpha) {return alpha;} break;
>>>> case hashfBETA: if(target->eval>=beta) {return beta;} break;
>>>> }
>>>>In which case mustn'nt we do a null-move ?
>>>>Thanks.
>
>>>If your hash record for a node (position) does not have enough draft to return
>>>from the search at this point, but does have enough draft
>>> (ie current_depth – R) for the null move search and predicts that it will
>>> not fail high (ie the stored hashflag is not a lower bound and the stored
>>>> value is < beta) then you can avoid the null move search for this node.
>
>I don't understand what means "draft". I would understand better a piece of code
>than a sentence, if possible.
>So you say :
>if(depth-R>0 && target->eval<beta)... DoNull=FALSE... ? :-)
>Thanks
if (type == UPPER && depth-R <= draft && tableval < beta)
avoid_null = 1;
Draft is "remaining depth" and is the depth value stored in the hash table...
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