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Subject: Re: Junior-Crafty hardware user experiment - 19th and final game

Author: Amir Ban

Date: 05:50:51 12/23/03

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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



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