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Subject: Re: Quiescence Explosion

Author: Sune Fischer

Date: 07:28:24 11/26/02

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On November 26, 2002 at 07:21:12, David Rasmussen wrote:

>On November 26, 2002 at 05:22:42, Dann Corbit wrote:
>
>>
>>Are you absolutely sure that the nodes are being counted correctly?  This is not
>>exactly a wild-open sort of position with scads of deep combinations in waiting.
>> It's hard to imagine how the qnodes can go berserk like that.
>
>I'm pretty sure I'm counting them correctly. I count only the nodes that
>Q-search _generates_, not the node I'm in on entering Q-search. Normally, my
>Q-percentage isn't that high. Before I got SEE, it was regularly in the 60%'s.
>Now, it is usually about 20-40%. But in this particular position (and the ones
>"near" it), and probably many others, the Q-search explodes.

You must have some extension that goes mad, like a threat extension or
something. I get around 55% qnodes, so you are right it is high but not _that_
high.

>I'm counting like this:

Why not do it like this:

>Score Search(pos,...)
>{
>   ++nodes;
>   ...
>   if (depth < ONE_PLY)
>       return Quiescence(pos,...);
>   ...
>}
>
>and
>
>Score Quiescence(pos,...)
>{
  // no counter here...
>   ...
>   while (anymore interesting moves)
>   {
>        ...
>        MakeMove(pos,move);
>        score = -Quiescence(pos,...);
>        UnMakeMove(pos,move);
>
>        ++qNodes;
>        ...
>   }
>}

Then you just have total nodes = nodes+qnodes and the percentage will be
nodes*100/qnodes. Cheaper to do 1 add outside the search of course.

-S.



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