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Subject: Re: Thanks for extracting this!

Author: Alessandro Damiani

Date: 04:46:50 01/01/06

Go up one level in this thread

On January 01, 2006 at 06:12:31, Uri Blass wrote:

>On January 01, 2006 at 05:24:30, Alessandro Damiani wrote:
>>On January 01, 2006 at 02:36:28, Uri Blass wrote:
>>>On December 31, 2005 at 20:50:30, Vincent Diepeveen wrote:
>>>>On December 31, 2005 at 20:20:47, Greg Simpson wrote:
>>>>>Vasik had very logical and persuave ideas.  I particularly liked the point that
>>>>>trading one third speed searching for twenty times the evauation per position
>>>>>almost has to be good if done right.
>>>>If that describes what he's doing then it seems however Vasik has taken the
>>>>other way around, the junior way. The utmost minimum of knowledge in leafs.
>>>I do not understand this comparison.
>>>Rybka is a slow searcher and Junior is a fast searcher.
>>>What is the reason that you think that rybka has minimum of knowledge in leafs?
>>How do you know Rybka is a slow searcher? Just by looking at its obfuscated
>>nps?? For instance, in
>>[D]8/8/pppppppK/NBBR1NRp/nbbrqnrP/PPPPPPPk/8/Q7 w - - 0 1
>>do you really think it takes quite long to find the mate in 1 because of a huge
>>static analysis? ;)
>In this case it does not show nodes per second but in the following position
>it shows nodes per second
>[D]8/8/pppppppK/NBBRQNRp/nbbrqnrP/PPPPPPPk/8/8 w - - 0 1
>Analysis by Rybka 1.0 Beta 32-bit:
>  +-  (2.46)   Depth: 3   00:02:22
>  +-  (2.46)   Depth: 4   00:03:01
>1.dxe4 dxe5
>  +-  (2.46)   Depth: 5   00:05:22
>1.Qxd4 Qxd5
>  +-  (2.77)   Depth: 5   00:06:16
>1.Qxd4 dxc5 2.Qxe4
>  +-  (3.06)   Depth: 6   00:08:19  4kN
>1.Qxd4 dxc5 2.Qxe4 Bxd5
>  +-  (3.06)   Depth: 7   00:12:59  18kN
>(,  01.01.2006)
>For some reason it searches only 4000 nodes in 499 seconds.
>This really seem strange that static analysis takes so much time
>I could believe 100,000 nodes per seconds on My A3000 and even 10,000 nodes per
>seconds but less than 10 nodes per second is even too much for me to believe.
>It seems that Vasik searches many nodes in what he counts as nodes.
>Maybe he is using different function and not using his normal makemove in the
>qsearch but it is clear that he searches a lot of legal moves inside of what he
>considers as evaluation so I cannot consider it as evaluation.
>I think that static analysis can consider trapped pieces so you can consider
>some moves without making them to check for trapped pieces but what I see in
>rybka is clearly too much for what I consider as static analysis.
>I think that recursive search of moves with more than one move per side cannot
>be considered as part of the evaluation.

Exactly. Static analysis is a 0-ply search, search being an operation which uses
making/unmaking of moves.

With my previous message I wanted to say this: you cannot imply from low nps
that an engine is a slow searcher. For instance, by just not counting quiescence
nodes an engine will have a low nps.


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