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Subject: Re: What is the average nodes per second for minimax?

Author: blass uri

Date: 09:47:05 06/19/00

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On June 19, 2000 at 11:40:26, leonid wrote:

>On June 19, 2000 at 06:41:52, blass uri wrote:
>
>>On June 19, 2000 at 00:32:26, leonid wrote:
>>
>>>On June 18, 2000 at 19:18:10, Tom Kerrigan wrote:
>>>
>>>>lenoid, do not call material evaluation "positional." They [basically] have
>>>>nothing to do with each other. Also, do not refer to evaluations as "partial" or
>>>
>>>
>>>Logic that deel with material echange is for me 100% positional logic. Reason is
>>>simple - slightest change in position on the chess board lead sooner or later to
>>>some material lost or gain. If you look into material echange, you look into
>>>position on it as well.
>>
>>People do not use the word positional for material.
>>
>>positional evaluation is the part of the evaluation function that is not about
>>counting material.
>>
>>When somebody wins material in game it is called tactics.
>>Positional understanding is about the value of the not material factors.
>
>
>And why somebody would like to even care about "positional understanding"? Not
>for the sake to reach somewhere material gain?
>
>Don't accuse me to be too materialistic. I am not true capitalist. I hardly have
>some money on my bank acount.
>
>
>>Positional understanding is important in chess because there are position when
>>one side has less material but better position.
>
>
>Better position that lead later to some material advantage? If you will look
>into this through the logic of material echange, you will reach "positional
>understanding" of this position in a very "natural way".
>
>
>>If you search deep enough you can see that the side with material advantage is
>>losing but there are cases when you need to see 50 plies forward to see that the
>>side with material advantage is losing and computers cannot see it by search.
>
>If material echange deep 50 plies will reveal something about position, fact is
>still there - material echange say everything about this position.
>
>
>>A good program must have positional evaluation that tells it in part of the
>>cases even without search that the side with material advantage is probably
>>losing.
>
>Agree! But this is only because material echange can't see that deep in most
>places. We must, at least, have some general guide line when we don't know where
>to go through perfect calculation of material. Those guide lines, that say where
>to go when we don't know for sure what to do, are called tactics.

No
The guide lines that say where to go when we cannot calculate are called the
evaluation function.

Tactics is about search and not about evaluation function except material.

If we can see by search that we win material it is tactics but in most of the
cases we cannot see by search that we win material and only material evaluation
will give the value 0.00 after search.

I believe that even if we assume that programs are 100000 times faster they
cannot search deep enough to see winning material in most of the positions.

 We are still
>very much in this domain because our computers are very weak. Before it was even
>more so. I even presume that "tactic" 20 years ago was even more important that
>today. Pobably it will become less relevent after the next 20 years as well.

I believe that the not material part of the evaluation function will become more
important in the future.

If you see 2 plies deeper than your opponent tactics is important if both sides
cannot search deep and the not material evaluation is less important because
you can destroy a good position by one blunder.

If both sides can search deep the probability for tactical mistakes(losing
material) is smaller and the quality of the evaluation function is more
important.

Having a good evaluation function can push the program with the better
evaluation function to sacrifice material for initiative and to win the game.

I saw too many cases when one side sacrificed material when the win is too deep
to see by search to tell you that having big not material evaluations of more
than a pawn and in some cases more than 2 or 3 pawns is important for the
future.

>Reason for this - material echange say you everything about position and tactics
>all the time. Question is only: How far it can see?
>
>Leonid.

I believe that only material evaluation has no chance against GM's even if we
assume that programs are 1000000 times faster.

Uri



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