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Subject: Re: New Way to Evaluate Positions

Author: Ricardo Gibert

Date: 07:46:15 11/21/00

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On November 21, 2000 at 09:08:24, Bob Durrett wrote:

>On November 20, 2000 at 22:46:58, Ricardo Gibert wrote:
>
>>On November 20, 2000 at 21:39:17, Bob Durrett wrote:
>>
>>>Before launching into the "new idea," I must admit that I have never seen the
>>>source code for Fritz, Rebel, and any of the other commercial chess programs.
>>>Maybe this "new" idea is already being implemented, at least in part.
>>>
>>>NEW IDEA:
>>>
>>>If a program evaluates each new position from scratch, it will take a certain
>>>amount of processor time, and the software will take up a certain amount of
>>>space in memory, and the situation will be much the same for each position of a
>>>chess game.
>>>
>>>But what if the same [or equal] evaluation could be done in a fraction of this
>>>time?  How?  It is wasteful to throw useful information away, so find a way to
>>>use it.
>>>
>>>The answer may be to use an "evaluation" method which converges on the correct
>>>evaluation by means of an iterative process.  This process need not be
>>>restricted to evaluation of the current position.
>>>
>>>For some, this may require casting off self-imposed boundaries [doing it the way
>>>"it's done"] and moving into a new paradigm.
>>>
>>>If it is noted that consecutive positions are necessarily very similar, then a
>>>way should be sought to use the information gleaned in one position and to use
>>>as a starting point for the evaluation of the next position.  This may require
>>>finding a radically new way to do "evaluation."
>>>
>>>Similarly, two positions separated by two half-moves in a game are also very
>>>similar, although typically not as similar as two positions separated by a
>>>"distance" of one half-move.  This suggests that information obtained during the
>>>"evaluation" of a position might also be useful for positions separated by more
>>>than one half-move.
>>>
>>>One could extend this idea to positions separated by "distances" of many
>>>half-moves.  In fact, some of the information known in advance before the game
>>>begins [assuming starting from the usual starting position] should have some
>>>bearing on all of the positions which follow in a game.  The greater the
>>>"distance," the less the usefulness of the information.
>>>
>>>This idea could be used "backwards" as well.  Since positions in a chess game
>>>are reasonably similar if separated by some reasonably small distance, then the
>>>evaluations of positions could also be used to refine prior evaluations of prior
>>>moves.  This suggests some sort of iteration, maybe.
>>>
>>>As I understand it, hash tables contain precious little information about each
>>>position.  That would have to change to use this method.  In fact, the structure
>>>of hash tables and the way they are used would have to change.
>>>
>>>Information obtained from a position would have to be retained by the program in
>>>some manner.  The use of hash tables is the "current paradigm" way of doing it.
>>>But the information might also be stored in settings the values of integers used
>>>in loops, for example.  Innovation by programmers not bound by the boundaries of
>>>current paradigms might be needed here.
>>>
>>>It is not suggested that any ordinary beginning programmer could figure out the
>>>optimal way of doing this.  But wouldn't it be worth the pain and agony required
>>>of an innovative programmer if he/she could work out a practical way of doing
>>>this?
>>>
>>>Underlying message:  To produce big improvements in performance of chess-playing
>>>software, or any other kind of software, for that matter, it may be necessary to
>>>cast off the shackles of the assumption that "doing it the way it's done" is the
>>>only way.  One should look for new paradigms.  This "evaluation" idea is my
>>>attempt to do just that.
>>>
>>>Incidentally, the name "Shannon" could be mentioned.  Any scheme which throws
>>>away, repeatedly, large amounts of information is inferior in the sense that it
>>>is theoretically better to use most or all of the information available,
>>>assuming that a practical way to do that is found.
>>>
>>>
>>>Bob D.
>>
>>"Your idea" is ancient and is called incremental evaluation of which piece
>>square tables are a very simple example.
>>
>>It is pretty obvious you haven't taken the time to learn some rather basic
>>things about computer chess programming. Why waste your time (and ours)
>>reinventing the wheel?
>
>I guess you are right, Ricardo.  I will crawl back into my shell and close the
>door.  I certainly wouldn't wish to waste anybody else's time.
>

I must have been in a grouchy mood. Sorry.

>>
>>I also don't care for the use of the word "paradigm". This word is much overused
>>and many like me have come to associate it with the inflating the value of an
>>idea. I wince ever time I see it.



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