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Subject: Re: Futility @ 1/Extended Futility @ 2/Limited Razoring @ 3 = % node reduce?

Author: Stuart Cracraft

Date: 19:07:27 10/20/04

Go up one level in this thread

On October 20, 2004 at 01:29:54, Jeremiah Penery wrote:

>On October 19, 2004 at 23:02:18, Stuart Cracraft wrote:
>>On October 19, 2004 at 21:11:47, Jeremiah Penery wrote:
>>>Do you know if the conditions are ever being properly triggered?
>>>In a depth 11 search on WAC 175 (a position I picked at random), I have these
>>>statistics in a modified Crafty with the pruning described below:
>>>Elapsed Time: 28.77, CPU Time: 27.62, CPU Use: 96%
>>>Root Material Balance: -200, Predicted Moves: 0
>>>Nodes: 12146603, Evaluations: 9251784, FH%: 97%, NPS: 422k
>>>Threat: 174, Check: 679610, One Move: 21736
>>>Passed Pawn: 920, Recapture: 24192
>>>PRUNING->  Futility: 4329693, Razors: 405194
>>>I implemented a variation of the Heinz/DT futility in Crafty (instead of
>>>returning a static score where pruning happens, I had it drop into qsearch for
>>>much more accuracy).  I don't know how the node count compares to a regular
>>>version, or how much the savings for futility is.  I'm sure someone else can run
>>>a default Crafty with futility on and off and report the exact differences.
>>Mine (depth 11, wac 175):
>>nps=68016 ha=22.00% q=66.0% bc=56% br=3.01% mp=139<>117
>>pawnx=2658 recapx=51744 qcheckx=0 checkx=129985 qfutilx=2374715 onereplyx=8428 m
>>thrx=14 otherx=1354
>>Futility/Razor pruning count is only 1354 compared with 5M for Crafty.
>>Uh, Houston, I think we have something wrong.
>I remember when I tried implementing this that I had some strange issues that
>took a while to work out.  Some things in the DT implementation have to be
>changed to match the structure of your program, and it's very easy to have
>mistakes in those changes.
>I think you've posted the code before, but if you could do so again (or better,
>email it to me), I can try to take a look at it.  I can't make promises, but
>maybe I can come up with something. :)

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