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Subject: Re: Let's back off for a minute from Rc6

Author: Robert Hyatt

Date: 19:57:08 10/20/00

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On October 20, 2000 at 09:56:24, Wayne Lowrance wrote:

>On October 20, 2000 at 09:26:43, Robert Hyatt wrote:
>
>>On October 20, 2000 at 01:00:07, Ratko V Tomic wrote:
>>
>>>> IE if my program plays Rc6 and I can prove it is correct, I am happy.
>>>> If I can prove it is bad, even though it won the game, I am not happy.
>>>> If I can't prove it either way, I am concerned.  That was the point
>>>> here.  I want my fate in my hands, not resting on whether my
>>>> opponent overlooks something or not.
>>>
>>>You are idealizing ability of risk-averse programs. If it were tic-tac-toe
>>>you can prove move is correct. But in chess, just because some hand-put
>>>tangle of evaluation terms gives, say, 0.3 pawns more for move A than
>>>for other moves B, C,... you haven't proven move A is correct. It is
>>>only "correct" within the model game (-tree) your program substitutes
>>>for the full chess tree (where every leaf is win, draw, loss).
>>
>>You are making the assumption that "heuristics" cannot be "accurate".  I
>>can give you lots of examples where this is a false assumption.  IE try to
>>play a simple k and p vs k ending against Crafty.  With no tablebases.
>>It only takes a few heuristics to play this perfectly, as any good endgame
>>book whill explain.
>
>That is very narrow thinking, picking out simplistic examples, the big picture,
>the whole game is another story. Bob do you think there are many perfect games
>played by a player ? even one ?
>
>Wayne
>>



Not only do I think there are perfect games, I am certain enough about it
to say "absolutely".  And not just a few either...



>>
>>>
>>>And only the final outcomes (and lots of them) can tell you which toy
>>>model of the game simulates the real game best. That is the criteria
>>>not only for some complex positional terms, but for every term, as much so
>>>for Knight = 3 Pawns as for "this particular king attack" = 3 pawns.
>>>
>>>There is no rule of the game which lets you "cash in" at will your
>>>Knight for 3 pawns, or the other way around, just as there is no
>>>rule letting you "cash in" some king-attack poise for 3 pawns. Both
>>>figures 3 are pure constructs of the respective models, they're little
>>>wheels in a toy which is trying to simulate the real thing.
>>>
>>>So, Crafty is only "correct" or "accurate" in following its model game, while
>>>Gambit Tiger is as "correct" or "accurate" in following its own model game. The
>>>two are two different model games (somewhat similar, well, yes), and neither
>>>model game is the full chess tree (not even close). And whichever one beats the
>>>other more that one has better model of the game, the model overall closer to
>>>the object it models.
>>>
>>>From this more abstract perspective your objections to GT's "risk taking" is of
>>>this kind: I see that odd wheel in that toy model, and if I were to put it into
>>>my toy model (or any model I understand or can imagine) it would wobble and slip
>>>so much that my whole toy model would fall apart. Therefore, that is a bad
>>>little wheel, and the whole model which has it can't be very good or solid. The
>>>only thing that really follows is that it's a "bad little wheel" if it were
>>>transplanted into your model game, not necessarily bad for Gambit Tiger's model
>>>game, much less for all other possible model games simulating chess.
>>
>>I don't know whether the speculativeness of GT is good or bad.  I simply brought
>>up the possibility that if a program 'gambits' away positional advantages for
>>other positional advantages, it is perhaps not a game-winning/game-losing
>>decision.  But if you gambit away a piece, a mistake will change the game
>>outcome significantly...



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