Author: Christophe Theron
Date: 15:25:26 12/23/03
Go up one level in this thread
On December 23, 2003 at 09:49:27, Anthony Cozzie wrote:
>On December 23, 2003 at 08:50:51, Amir Ban wrote:
>
>>On December 23, 2003 at 08:09:34, Uri Blass wrote:
>>
>>>On December 23, 2003 at 06:47:18, Amir Ban wrote:
>>>
>>>>
>>>>Thanks for running this match and for the interesting commentary.
>>>>
>>>>My point in playing this match was never to show how weak crafty is, but
>>>>something different: Too many programmers and posters in this forum take the
>>>>speed issue way too seriously. They don't understand the importance of
>>>>evaluation, and when they do think about it, they think it's about pawn
>>>>structure and a few super-rare endgame tableaus.
>>>>
>>>>I also needed to check that I've not been wasting my efforts in the last few
>>>>years.
>>>>
>>>>Merry Christmas and Happy Hanukka,
>>>>Amir
>>>
>>>I do not claim that evaluation is not important but my opinion is that search is
>>>not thing that is less important.
>>>
>>>I also know that inspite of the fact that you say that evaluation is important
>>>your evaluation takes only 20% of Junior's time(I do not know about latest
>>>Junior but I know about previous post of you).
>>>
>>
>>Less than 10% in most positions.
>>
>>
>>>How is it possible?
>>>
>>>Did not you find important things to evaluate that it is simply impossible to
>>>evaluate them fast?
>>>
>>
>>There are many things I can do basically for free in my framework. There are
>>things that break the model, and either are neglected or if considered critical
>>get done outside it.
>>
>>
>>>For example let talk about pieces that are in danger of being trapped because
>>>the opponent control every square that they can goto.
>>>
>>>There are cases that you need to search many plies forward to see by search that
>>>they are really trapped but a good evaluation should detect the danger.
>>>
>>>Correct me if I am wrong but I guess that you do not evaluate this information
>>>in every node that you evaluate otherwise you cannot be faster in nps than the
>>>opponents.
>>>
>>>Did you consider to evaluate this information or do you think that this
>>>information is not important?
>>>
>>
>>I do this for some important special cases. Not in the general case. It's hard
>>for me to guess how productive that would be.
>>
>>
>>>I think that evaluating expensive information in part of the cases is probably
>>>the best practical idea.
>>>
>>>Based on my understanding Rebel is using that idea when it evaluates every node
>>>before qsearch by full evaluation and use lazy evaluation after it when the lazy
>>>evaluation can miss only factors that were not relevant before the qsearch.
>>>
>>>Do you use a similiar idea?
>>>
>>
>>No.
>>
>>You are confusing between the evaluation elements and its result. Both are
>>important, but it's still true that your evaluation of a position can use a lot
>>of smart and correct elements and be totally off, and it is equally true that it
>>can be right though neglecting a lot of important stuff.
>>
>>Amir
>
>
>It seems like you and Christophe have some tricks up your sleeve. He's been
>making comments like this for some time about his new 'Fugu' thing. It looks
>like I'm going to have to do some serious thinking :)
>
>anthony
The basic thinking with Fugu is that I'm fed up of evaluating every position. I
want Chess Tiger to be able to understand which positions do not need more than
a pure material evaluation, and which positions must be evaluated positionally
very precisely.
Another idea is to have an engine that performs two searches at the same time: a
very deep, full speed tactical search, and a less deep, very slow positional
search. The problem is what to do with the two results when they differ... :)
Christophe
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