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Subject: Re: ETC

Author: Tony Werten

Date: 04:06:50 12/04/02

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On December 04, 2002 at 06:58:10, Lars Bremer wrote:

>>>	// MakeMove
>>>	// Check for Draws.
>>>	// Extensions for this move.
>>>	tdepth=depth-1+extension;
>>>	hit=HashRetrieve(pboard,tdepth-1,&tscore,&flag);
>>>	// UnMakeMove
>>>	if (hit)
>>>	{
>>>		tscore=-tscore;
>>>		if (tscore>=beta && (flag==upper_bound || flag==exact_value))
>>>			return (tscore);
>>
>>I think this should be : if (tscore>=-alfa) ...
>>
>>You're using current beta, but you want beta for the next move ( wich is -alfa )
>
>Hi,
>
>no, you're wrong I think. He is looking for a beta-cutoff on the actual depth
>with the evaluation from a hashmove one ply deeper in the tree (tscore=-tscore),
>so he has to use the actual beta.

I think you're right.

Shouldn't where tscore to -tscore is changed, also the flag be changed ?

if tscore>5  (lower bound )  then -score<-5 (upper bound)

I hate this crap. That's why I threw etc out.

Tony

>If he would be interested in possible cutoffs
>one ply deeper, your "tscore>=-alfa" is correct, this would be a kind of
>hyper-ETC :)
>
>cu
>
>Lars



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