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Subject: Re: Is the NPS tend to grow at the end of the game?

Author: Josť Carlos

Date: 07:02:49 07/22/00

Go up one level in this thread


On July 22, 2000 at 09:37:22, Robert Hyatt wrote:

>On July 22, 2000 at 09:20:23, Josť Carlos wrote:
>
>>On July 22, 2000 at 08:46:25, leonid wrote:
>>
>>>Hello!
>>>
>>>Is the nodes per second number tend to grow when program search position more
>>>advanced in the game? When there are less pieces on the board.
>>>
>>>I just speeded my program in around 30% and tried to find where my nps is now.
>>>Went to the Fritz 6 counter (Fritz engin inside of Hiarcs package) and was
>>>disappointed. Fritz still keep me at the safe distance at the end of the game.
>>>This is due to the strange (for me) fact that Fritz numbers goes up at the end
>>>of the game. This time in mine nps goes down. In mine program less are the
>>>pieces on the board, less efficency in the search of the legal moves. Wanted to
>>>see if there are some general tendency in all programs. Before asking here my
>>>question, went to see Rebel 10. Its numbers looks like to be very stable. No big
>>>difference between heavy initial and final positions. Once again difference with
>>>my program.
>>
>>  My program (Averno) usually searches 300% faster (in nps) in the endgame. I
>>never have thought about it cause I saw it natural, but if I think a little, I
>>can give some reasons:
>>
>>  - My evaluation in the endgame is easier (no king-safety code).
>>  - Less moves generated = less time spent generating moves. :)
>
>This can hurt as well as help.  If you generate one move, the overhead for
>calling search recursively and so forth is spread over one move, rather than
>many...
>
>
>
>>  - Better use of trans/ref table (many more transpositions).
>>
>
>I'm not sure this should increase your NPS.  It sure ought to make your
>search go deeper, quicker, however...

  Yeah, your answer looks correct in both cases, so I'll have to think longer
about why the 300% increase... It can't be only for the king-safety evaluation,
because it's not that slow, maybe my mobility calculation hurts the nps ratio
when there're many pieces...
  Mmmm, something to think about this weekend.

  Josť C.

>>>Thanks for response,
>>>Leonid.
>>
>>  Hope this helps.
>>
>>  Josť C.



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