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Subject: Re: Furthermore...

Author: Chan Rasjid

Date: 19:13:29 12/15/05

Go up one level in this thread

On December 15, 2005 at 21:33:32, Chan Rasjid wrote:

>On December 15, 2005 at 17:44:24, Jaime Benito de Valle Ruiz wrote:
>>On December 15, 2005 at 17:05:00, Sergei S. Markoff wrote:
>>>1) Fruit.
>>>Fruit search seems to be primitive. "History pruning" is a variation of
>>>well-known idea. After implementing such method in SmarThink some years ago I
>>>named it "history-based pruning" and then changed to "ordering-based pruning".
>>>The outcome of such methods very depends of whole search model, but anyway
>>>history pruning is not the key to Fruit strength.
>>>To my mind, the key of Fruit strength is that the "Chess is the art of
>>>exchange". So, Fabien's idea about flexible game stages looks to be a beautiful
>>>way to improve positional play. Fruit can effectively consolidate the position.
>>>It simply knows when to excange to improve position. I think that it's the main
>>>key (cumulative with very good tuning of evaluation function). I think Fruit is
>>>very perspective. The main line of progress for this project, to my mind, is to
>>>add more complicated knowledge and intellectualize a search.
>>I completely agree with you. People overestimate FruitĀ“s search, and
>>underestimate its eval because it looks simple.
>I cannot comment expertly.
>It seems to me there are not many lines in Fruit's eval(). It seems even
>I could add more detail terms in its eval_pattern(). So it is confirmed a good
>simple evaluation can make a top program.
>Thomas of Toga should know something and he empasized on search extention
>and the way of Fruit's using nullmove. Does anyone think it wrong?
>>>2) Rybka
>>>Some time ago we discussed with Gian-Carlo Pascutto an idea of create special
>>>"SET-tables" with sets of piece-square values indexed by 1) material on the
>>>board; 2) king position; 3) pawn structure. Such tables can be calculated by
>>>analyzing a lot of games. That time I delayed my work in this area because I
>>>found other perspective things.
>>>You can see that Rybka executable contains a lot of precalculated tables. And
>>>also we all know that Rybka plays positional style. My version is that Rybka
>>>uses some variation of SET-approach. At all cases it uses some precalculated
>>>positional knowledge, but what sort of it? ;)
>>Interesting idea.
>The secret maybe in Rybka's readme file and some comments I read in recent
>threads about certain characteristic behaviour it displayed under certain
>circumstances and other things.
>Vasik, if you are here, am I totally off ?

There are about 4-6 top programs much above the rest and it may be those know a
few critital elements crucial for a very top program that all the rest missed.

Maybe what is most important may be what is the simplest as an idea. Newton's
law of motion may be summarized in three simple statements fully and a whole
book on classical mechanics may be written with just that.

Bugs - as others have pointed out here. You have the correct critical ideas
implemented perfectly but together with a few serious and insidious bugs - then
pray hard that they do not touch your critical lines of search. You then decide
the perfect illumination you got is false.


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