Author: Wayne Lowrance
Date: 06:56:24 10/20/00
Go up one level in this thread
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 > > >> >>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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