Author: Stuart Cracraft
Date: 18:59:39 08/10/04
Go up one level in this thread
On August 10, 2004 at 12:52:28, Robert Hyatt wrote:
>On August 10, 2004 at 10:59:29, Tord Romstad wrote:
>
>>On August 10, 2004 at 10:35:29, Anthony Cozzie wrote:
>>
>>>Plus, if you have only PST eval you should be getting 3-4M nps, so SEE probably
>>>slows you down a _lot_.
>>
>>Yet another proof of how bad my programming skills are. With PST eval and
>>nothing
>>else, I get about 800,000 nps (on a PIV 2.4 GHz). Adding SEE slowed me down to
>>around 750,000 nps.
>>
>>Tord
>
>
>SEE slowed me down by 10%. Move ordering improved to speed me up 10%. Washed
>out to no advantage, _until_ I added the stuff about tossing out captures that
>can't bring the score back to within the alpha/beta window. That made me about
>2x faster overall, which is a _big_ gain. Stuart isn't getting all the
>advantages of SEE yet, and, in fact, It isn't necessary to use SEE on _every_
>capture. IE for PxQ there is no need to see if that is +9 or +8. Either is
>good enough and there MVV/LVA is faster.
Then the question that is begged here is about "added the stuff about tossing
out captures that can't bring the score back to within the alpha/beta window."
I take this to be similar at what you hinted when you said if the capture
gets me back a pawn but I'm a queen down, why bother?
So are you talking about, in quiescence in move loop:
while next capture
if material_evaluation_after_this_capture + MARGIN < alpha
skip
else
if (see()<=0) skip
else
makemove
search
unmove
fi
fi
endloop
where MARGIN is like 2 pawns or something?
Stuart
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