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Subject: Re: null-move in PV?

Author: Will Singleton

Date: 12:02:23 11/20/98

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On November 20, 1998 at 11:03:09, Inmann Werner wrote:

>On November 20, 1998 at 09:35:46, Robert Hyatt wrote:
>
>>On November 20, 1998 at 06:28:01, Inmann Werner wrote:
>>
>>>
>>>Do you really make null moves in the PV. How do you manage, that Null moves do
>>>not get into the PV?
>>>
>>>Werner
>>
>>
>>Because when we do the null-move search, if it fails high we return beta
>>which means it *can't* get into the pv (failed high).  If it doesn't fail
>>high, we ignore it and do a normal search, which means something else will
>>get into the pv with the null-move being ignored totally.
>
>Thanks a lot, Robert and Peter!!!!
>
>This was one of the most simple and good tips, I got!!!
>I now use null move also in the PV, had to change only one variable in my
>program and my search tree is reduced by 40%!!!! (tested with 4 positions)
>It must be some brain-damage of me, why I did not recognize this of my own.
>There you go looking for speed increasments of 2 to 5 percent, and here you get
>a lot of this as simple!
>
>Thanks again
>
>Werner


40 percent?  Seems like a lot.  You might want to check your results on the full
WAC.  I would think you'd solve a lot more with the added depth, and if not,
then you've got a problem.  I'd be interested in knowing.

Will



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