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Subject: Re: Branching factor, etc

Author: Bas Hamstra

Date: 05:17:37 09/01/02

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On September 01, 2002 at 07:47:59, Tony Werten wrote:

>On September 01, 2002 at 06:29:16, Bas Hamstra wrote:
>
>>>Now suppose FP is right but we don't prune. What happens ? We go to quiescence;
>>>evaluate; get a score above beta; and cutoff. So no nodes saved.
>>>
>>>FP can only save nodes when we would otherwise spend time in quiescence; ie
>>>score is not above beta ie fp was wrong.
>>>
>>>People who report big wins with fp probably have an "inc(nodecounter)" in the
>>>top of quiescence, wich doesn't get called when pruning.
>>
>>Couldn't agree more. Those nodecounts are very misleading, what counts is depth.
>>And once you measure that, it suddenly isn't so great anymore. Heinz bases his
>>research on nodecounts. But the nodes saved are "cheap" nodes, that are
>>_accurately_ cut by lazy eval with little cost anyway. FP is good for picking op
>>wood in blitz, not much more.
>>
>>But regarding SEE, not doing it MUST mean a fairly higher qrate, no? It slows
>>you down and gets somewhat better in tactics. Only I hardly see that tactical
>>advantage, really. Of course it might depend on your qsearch. Mine is typically
>>2-3 x bigger than a Crafty like miniqsearch, not doing SEE would make it even
>>worse.
>
>It's a choice. From games XiniX played I always had the feeling it should
>improve in tactics. The positional evaluation was quite exact but it happened
>too often: I have a good position, I have a good position, I have a good
>position, oops that costs a knight.
>
>Now my first few ply in Qsearch are very simular to a normal search.
>
>Tony

Interesting. I tried that also, and it found good things sometimes. I threw it
out because it slowed me down too much. But I still think it's interesting,
especially if you find a way to throw out quiet nonsense moves. You must have a
hell of a qrate now, or not? As compared to a Crafty like qsearch, what is your
qrate? Mine is about a factor 2,5 and yours? Must be even worse?

Best regards,
Bas.










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