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Subject: Re: Crafty node count question

Author: Robert Hyatt

Date: 17:05:27 03/02/04

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On March 02, 2004 at 18:07:18, Volker Böhm wrote:

>On March 02, 2004 at 15:05:33, Robert Hyatt wrote:
>
>>On March 02, 2004 at 14:50:43, Volker Böhm wrote:
>>
>>>Hi,
>>>
>>>in the post "Simple rook sac" I´ve found the following crafty analysis result:
>>>
>>>    time=8:36  cpu=395%  mat=1  n=1370692317  fh=92%  nps=2.66M
>>>    ext-> chk=58001759 cap=3294306 pp=293332 1rep=5509951 mate=376022
>>>    predicted=0  nodes=1370692317  evals=299470745
>>>    endgame tablebase-> probes=0  hits=0
>>>    SMP->  split=2056  stop=369  data=9/32  cpu=33:59  elap=8:36
>>>
>>>Crafty got 300M evals and 1370M nodes.
>>>My Question:
>>>
>>>Why has crafty got that much less evals than nodes? What does crafty count as
>>>node and when does crafty don´t need to eval. Non leaf-nodes, hash-hits with
>>>right depth and value range, anything else?
>>
>>all of those, plus "lazy eval" cutoffs that avoid doing a full eval...
>
>When do you use lazy eval? If (material + bonus < alpha) || (material - bonus >
>beta)? how big is bonus? Do you count passed pawns in "material"?
>For me passed-pawns + king-attack + pawn-shield could get up to 6  pawns
>"positional" value. Is your bonus much less than your theroretical positional
>value?
>
>Thanks!

I remember the largest positional score and always use that for "bonus"

I do all passed pawn evaluation for every position.  I only skip the normal
scoring stuff that is slow to compute and limited in score...



>
>Greetings Volker
>
>>
>>
>>>
>>>My engine is doing eval at every horizont position and at every q-Search
>>>position. My engines evals/nodes is about 0.8.
>>>
>>>Greetings Volker



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