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Subject: Re: Is the NPS for minimax devided by NPS in alpha-beta = 5 ?

Author: leonid

Date: 12:49:35 06/16/00

Go up one level in this thread


On June 16, 2000 at 15:00:26, blass uri wrote:

>On June 16, 2000 at 14:54:18, leonid wrote:
>
>>On June 16, 2000 at 14:12:47, Tom Kerrigan wrote:
>>
>>>On June 16, 2000 at 14:10:24, leonid wrote:
>>>
>>>>On June 16, 2000 at 13:25:41, Tom Kerrigan wrote:
>>>>
>>>>>On June 16, 2000 at 13:16:57, leonid wrote:
>>>>>
>>>>>>On June 16, 2000 at 12:34:58, Michel Langeveld wrote:
>>>>>>
>>>>>>>No nps of alpha-beta and minimax will be almost the same. But the total number
>>>>>>>of and the total amount of time will be a much lesser.
>>>>>>
>>>>>>Your first statement sound to me as something near to impossible. Just recently
>>>>>>Bas Hamstra said that minimax speed is around 800000 nodes/second. Computer was
>>>>>>indicated as Pentium 466M. Usual number of nodes/second that I see on my AMD
>>>>>>400M (for some best chess games like: Crafty, Xchess, Comet...)is around 150000.
>>>>>>Even from this I can see that: 800000:150000=5.3 times.
>>>>>
>>>>>Then his program is 5.3 times faster. This has virtually nothing to do with
>>>>>alpha beta vs. minimax.
>>
>>So, what your obove sentence say? In simple term? That 800000 NPS is just usual
>>speed (or more exactly, number of positions seen) of its program? Never mind if
>>logic use minimax or alpha-beta? Number of positions seen is always 800k?
>>
>>Leonid.
>
>I think that he means that 800000 nps is usual speed if you want to use alpha
>beta+only material evaluation and when your program is as fast as possible in
>nodes per second(this means that you do not have extension rules and that you do
>not try to use good order of moves)
>
>Programs usually do not do it because programmers want to develop better
>programs and not to be the champion in nodes per second so they are slower in
>nodes per second.

Uri, if the best program "factor" between minimax and all the "perfection" is 5
but in other program 3, useful information is found. When it is 3, it could be
the indicative that programmer must look into its move ordering and so like.

Leonid.



>Uri



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