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Subject: Re: quiesce node explosion

Author: Volker Böhm

Date: 13:45:36 01/24/04

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On January 24, 2004 at 16:20:14, Mike Siler wrote:

>On January 24, 2004 at 16:07:04, Volker Böhm wrote:
>
>>On January 24, 2004 at 15:57:50, Mike Siler wrote:
>>
>>>In an average middlegame position, around 80-85% of the nodes my program
>>>searches are quiesce nodes. I have a static exchange evaluator and I only search
>>>captures with SEE value > 0. It seems like other engines are always under 25%
>>>qnodes. What else should I be doing to reduce these numbers?
>>>
>>>Michael
>>
>>What do you count as quiesce node? Do you count a totally quiet horizont
>>position a quiesce node? If yes, 80-85% is ok. Else you´ve got a bug.
>
>Every time quiesce() is called, I increment qnodes.
Suppose you search 1 ply deep with only two kings on the board (no hit moves
possible). Whits turn, white got 9 moves to go. Do you call quiescence 9 times
for eval and count 9 nodes?
Then all is ok as you count the horizont positions as quiesce.


>
>>
>>To reduce nodes in quiesce:
>>
>>1. if static-eval > beta -> finished
>
>That much, I've already got.
>
>>2. if static-eval + piece-to-hit + bonus < alpha -> prune.
>
>I just added this, but it didn't seem to make much difference. I suppose I
>probably have some sort of bug.
>
>>
>>that should be enough to reduce nodes to 25% if not searching "bad SEE hits"
>>
>>P.S. search if SEE == 0 too
>>
>>Greetings



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