Author: Ratko V Tomic
Date: 08:24:34 10/20/00
Go up one level in this thread
>>> 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.
>
I didn't say that risk-averse programs have no abilities. (Endgame rules,
table-base positions or any other position with shallow enough min-max outcome
are all within their abilities.)
What I am saying is that you have set up "happiness" criteria which ought to
make you "concerned" in most positions since you won't be able to prove the move
seleceted is the best/most accurate one. Just because it may appear "best" in
your Crafty's model game tree, it doesn't mean you have proven it the best and
that now you have your "fate in your own hands." It so only to the degree the
model game your program creates approximates the real game tree. If GT's model
game, after sufficient number of games, turns out to be closer to the real game
than Crafty's model, than you can only stay "concerned" with fingers crossed
when playing against it, no matter how happy Crafty may appear with its accurate
evaluations.
> 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...
Almost every move "gambits away" all the alternatives. You are enshrining
"material value" as if it were part of the rules of the game, i.e. as if somehow
the chess rules allow you to 'cash in' at will your knight for, say, 3 pawns,
but they don't allow 'cashing in' at will some king attack poise for 3 pawns.
The rules allow one as much as the other, no matter what the program's wood
count says is the "value" of this or that.
Now, it's true that it is much easier, especially for the less sophisticated
algorithms, to hold onto a material than to keep an initiative or a king attack.
But if GT knows how to maintain and transform favorably those seemingly more
"fragile" ("fragile" for the less sophisticated algorithms) traits of a
position, they're as good and solid measure of position as the "material value."
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