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Subject: Re: Toga 1.0 and the bad bishop

Author: Ryan B.

Date: 15:08:26 10/13/05

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Shredder over pruned and lost this time I guess.  I cant test it for sure
because I don't have a windows computer or Linux ver of shredder but from when I
had access to a windows computer I noticed Shredder would sometimes prune out
moves that it should not relating to king safety.  This is not an eval issue it
is a search tree issue.  It is rarely Fruits almost non-existent eval function
that wins games, it is its amazing search tree stability and accuracy.  If you
don't believe me try making movei's eval just like fruits.  I think it would be
called gutting your eval function though.

On October 13, 2005 at 15:44:22, Uri Blass wrote:

>On October 13, 2005 at 13:32:58, Ryan B. wrote:
>
>>On October 13, 2005 at 06:26:05, Uri Blass wrote:
>>
>>>On October 13, 2005 at 03:02:45, Ryan B. wrote:
>>>
>>>>I think it is a known issue that Toga, just like Fruit that it is based on,
>>>>knows very little about stratrgy and plays off being a great searcher.
>>>
>>>
>>>No
>>>
>>>I think that evaluation is one of the big advantage of fruit relative to
>>>opponents and not search.
>>>
>>>I have examples when Fruit simply evaluate position better than commercial
>>>programs.
>>>
>>>
>>>  Becuase
>>>>it is an open source program you could add to the eval but it will slow down the
>>>>search some for each thing added.  In computer chess it is still tactics over
>>>>strategy, never mind the so called "positional" chess programs.
>>>
>>>I disagree.
>>>I think that there are lot of positions that fruit understand better than
>>>commercial programs(see the case of the exchange sacrifice that I mentioned)
>>>
>>>Fruit is also not a fast solver of nolot 1 or nolot 2 so I do not think it's
>>>relative advantage to the commercial programs is tactics.
>>>
>>>Uri
>>
>>
>>Fruit understands the exchange sacrifice you mentioned because it has no bad
>>trade value.  I am sure it could also get burned on not having one.  Not that a
>>bad trade value is good chess knowledge becuase it is just a lazy assumption
>>that is usualty right.
>
>The exchange sacrifice is not the only case
>
>look at the last game of the following post
>
>http://www.talkchess.com/forums/1/message.html?455583
>
>
>Here is a position from that game
>
>[D]3r1k2/5p1p/3b2r1/5pp1/Pp1B2n1/1P2PB2/4QP1q/R2R1K2 b - - 0 27
>
>Fruit has positive score for black when Shredder evaluates it as better for
>white and need time to see positive score for black.
>
>What is the reason that shredder evaluates it as better for white at small depth
>if not inferior knowledge relative to Fruit.
>
>I think that fruit is simply better evaluator than Shredder and
>Fruit2.2 can beat Shredder inspite of being often outsearched by shredder
>because of a better evaluation.
>
>Uri



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