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Subject: Re: Beginner questions

Author: Pham Minh Tri

Date: 20:37:52 10/21/00

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On October 21, 2000 at 17:55:22, Georg v. Zimmermann wrote:

>On October 21, 2000 at 09:11:12, Pham Minh Tri wrote:
>
>>My questions are:
>>- If I add more knowledge to the evaluation function, how does AlphaBeta
>>function change (will the number of searched nodes increase, decrease or not
>>change)?
>
>If you add more knowledge, your program will probably spend more time in the
>eval() function. That way taking longer every time at the "leaf" of the search
>tree the evaluation is called. Threfore you will serach less nodes.
>
>How much this will make your program slower depends on what time - percentage it
>spends in which parts of the program before your change. If you have a very fast
>evaluation and slow bitboard move generation adding to the eval() will not cost
>you much.
>
>
>>- If I do not sort or sort move list by other criteria, could score and move
>>results be different?
>
>No, you should get exactly the same scores and moves after finishing a certain
>depth. The last move of the PV could change though in certain cases if I am
>making no thinking mistake.
>
>>
>>Your answers will help my implementation much. Thanks in advance for any help.
>>
>>Pham
>
>
>Have fun with your program !
>
>Georg

Thanks for your answer. However, we misunderstand some aspects of questions:

1) I know that adding more knowledge makes searching slower, but how about the
number of searched nodes (without attention to search time) when there are more
"resolution" in the evaluation?

2) I think the resulted move could be diffirent when there are some of the best
moves (equal score). And I wonder if nullmove, razor and so on could affect the
resulted score when search finds another best move.

Pham



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