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Subject: Re: So why the difference between 32-bit and 64-bit versions?

Author: Uri Blass

Date: 22:32:48 01/15/06

Go up one level in this thread


On January 16, 2006 at 01:18:14, Keith Ian Price wrote:

>On January 16, 2006 at 00:57:35, Uri Blass wrote:
>
>>The reason is simple.
>>It is known that many programs simply evaluate repetition as a draw and rybka is
>>one of them(many programs are going to see a draw in the same conditions).
>>
>>It is the simple solution to the problem of avoiding repetitions.
>>
>>programs of course can evaluate only 3 time repetition as a draw but it may
>>cause them to search bigger trees for no good reason so it is not clear if it is
>>better for playing strength.
>>
>>programs that evaluate first repetition not as a draw may waste time by allowing
>>repetitions and in some cases it even may cause draw by the 50 move rule because
>>in superior position they may not be able to be lucky to find the right plan on
>>time when avoiding repetition may force them to find the right plan if they
>>evaluate first repetition as a draw.
>>
>>I choose to evaluate first repetition as a draw because when I have 2 options
>>when it is not clear which one is better I prefer the simpler option.
>>
>>Uri
>
>Well, I thought that might be the case, but why does the 32-bit version evaluate
>it as losing, while the 64-bit version thinks it's a draw. And should the
>program evaluate a non-forced repetition as a draw, if it is so far behind?
>
>kp

I do not know Rybka 1.0 beta 32-bit see a draw when it get the game and not
losing score for black.
Maybe latest 32 bit version is different.

Deep Shredder 9.02 x64 - Rybka 1.0 Beta, Blitz:16' 2005
b1r1qn1k/1rb3p1/2p1p2p/2N1P3/1P1P4/R2B1N2/3Q1PPP/2R3K1 b - - 0 1

Analysis by Rybka 1.0 Beta 32-bit:

43...Rbb8
  =  (0.00)   Depth: 3   00:00:00
43...Rbb8
  =  (0.00)   Depth: 4   00:00:00
43...Rbb8
  =  (0.00)   Depth: 5   00:00:00
43...Rbb8
  =  (0.00)   Depth: 6   00:00:00
43...Rbb8
  =  (0.00)   Depth: 7   00:00:00
43...Rbb8
  =  (0.00)   Depth: 8   00:00:00  1kN
43...Rbb8
  =  (0.00)   Depth: 9   00:00:00  1kN
43...Rbb8
  =  (0.00)   Depth: 10   00:00:00  2kN
43...Rbb8
  =  (0.00)   Depth: 11   00:00:00  3kN
43...Rbb8
  =  (0.00)   Depth: 12   00:00:00  7kN
43...Rbb8
  =  (0.00)   Depth: 13   00:00:01  12kN
43...Rbb8
  =  (0.00)   Depth: 14   00:00:01  18kN
43...Rbb8
  =  (0.00)   Depth: 15   00:00:01  28kN
43...Rbb8
  =  (0.00)   Depth: 16   00:00:02  48kN
43...Rbb8
  =  (0.00)   Depth: 17   00:00:03  85kN
43...Rbb8
  =  (0.00)   Depth: 18   00:00:04  148kN
43...Rbb8
  =  (0.00)   Depth: 19   00:00:05  250kN
43...Rbb8
  =  (0.00)   Depth: 20   00:00:06  402kN

(,  16.01.2006)

Uri



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