Author: Daniel Shawul
Date: 06:14:21 04/08/04
Go up one level in this thread
On April 08, 2004 at 09:04:15, Harald Lüßen wrote:
>On April 08, 2004 at 07:10:29, Daniel Shawul wrote:
>
>>Hi
>>Here are some questions
>>
>>2.In Ed's paper there are some tricks done at horizon.
>> trick one if(score - (margin + largest hanging piece) > beta)
>> don't do quiescence
>> trick two if(score - 900 > beta)
>> don't do quiescence
>> My question is every body does
>> score=eval()
>> if(score > beta)
>> don't do quiescence;
>> So i don't see how the tricks work?
>
>His alpha is our beta and vice versa.
>
>I do:
>int search( depth, alpha, beta )
>{
> score = evaluate();
> // pruning tricks here
> while ( moves )
> {
> do_move();
> score = -search( depth-1, -beta, -alpha );
> undo_move();
> }
>}
>
>Ed perhaps does:
>int search( depth, alpha, beta )
>{
> while ( moves )
> {
> do_move();
> score = evaluate();
> // pruning tricks here
> score = -search( depth-1, -beta, -alpha );
> undo_move();
> }
>}
>
>Translated to my function his tricks would look like:
>trick one if(score + margin + opponents_largest_hanging_piece < alpha)
> don't do quiescence
>trick two if(score + 900 < alpha)
> don't do quiescence
That is better and understandable.But isn't this similar to delta pruining?. But
are you sure he means alpha when he says beta in all the paper. in lazy
eval,futility etc. I shall have to check that again.
>And that I can understand.
>
>Harald
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