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Subject: Re: High NPS vs. Low NPS

Author: Josť Carlos

Date: 10:50:42 11/26/01

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On November 26, 2001 at 10:51:25, Uri Blass wrote:

>On November 26, 2001 at 10:45:44, Michael Borgstaedt (GOLIATH CHESS) wrote:
>>On November 26, 2001 at 10:19:17, Steve Maughan wrote:
>>>>Less than 5% of the evaluation in Goliath (Light 1.5) is done by "piece-table
>>>>evaluation". Besides, nearly no prescanning is done. The latest version (which
>>>>won the blitz tournament during the WM/Maastricht) comes without any type of
>>>>prescanning or piece-table evaluation. Little/Light Goliath uses much (!) more
>>>>chess knowledge than many users would expect. But Goliath is still extremely
>>>>fast and the only "secret" is the way, how I realized the cooperation between
>>>>search and knowledge. This has nothing to do with "lazy evaluation". Goliath
>>>>uses a special "oracle" which decides, how much and what type of knowledge will
>>>>be used for the reached leaf position. And, of course, the essential parts of
>>>>the program (search, make/unmake move and so on) are highly optimized for
>>>I stand corrected!!
>>>Impressive speed indeed if you are doing mostly leaf node evaluation.  A couple
>>>of questions: are you defining nodes as all legal move calls to AlphaBeta and
>>Yes, the usual way.
>I think that the usual way is considering illegal moves also as nodes.
>I know that Crafty generates illegal moves as nodes except cases when the king
>is in check and Crafty generates only legal moves.
>Does Goliath consider illegal moves that puts the king under threat as nodes and
>if the reply is positive in which cases?

  I don't think it's the usual way to count illegal moves. I do nodes++ at the
end of makemove, only when I know the move is legal and return(TRUE).
  I believe most people don't count illegal moves.

  Josť C.

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