Author: Komputer Korner
Date: 22:41:04 05/24/98
Go up one level in this thread
On May 25, 1998 at 01:38:24, Komputer Korner wrote: >On May 23, 1998 at 17:10:56, Robert Hyatt wrote: > >>On May 23, 1998 at 14:18:04, Ren Wu wrote: >> >>>I think KK miss the point here. >>> >>>Don's paper has outlined a framework to apply TD methods to chess >>>evaluator. In fact, it is not just for chess, his framework can be >>>easily applied to most other games as well. And what it can learn is not >>>just piece values but can be any evaluaion terms. For me, the method, >>>or the way to solve the problem, is a lot more important. >>> >>>I doubt that the search depth will effect the knight value that much, >>>but that is once again not the point, the point here is the way doing >>>things, not the experiment results. >>> >>>If you suspect that search depth will effect the knight's value, why >>>don't you repeat the experiment but with greater depth? And report the >>>result here. Even if you come up a vast different values, there is still >>>no flaw in this framework, because you are still in the same framework. >>>The framework has no search depth limitations. >>> >>>There is no major flaw in that research. ( And maybe there was flaws in >>>your way to look things. :-) ) >>> >>>Ren (renw@iname.com) >> >> >> >>the biggest "flaw" was that Alan looked at "the result of the results" >>rather than at "the results". The learning looked good to me. Just >>because >>the piece values appear to be "a little different" is not cause for >>alarm >>IMHO. First, there's nothing to say that 1,3,5,9 are right (I don't use >>those, for example.) And there is also nothing to suggest that the >>values >>might be different depending on the "core" of the program being used to >>learn the values... IE a program with strong pawn structure analysis >>might have a pawn value > 1, while a strong tactician might have >>knight/queen >>!= 3,9, and so forth... > > >The 1,3,3,5,9 ratio has stood the test of time with the only other >significant one that I have seen is the one by Larry Kaufmann who put it >at 3,10,10,15,29 3=pawn 29 = queen with the 2 bishops =21 >These point counts are important and I didn't question the experiment >itself. I simply questioned the lack of search depth for a chess >experiment that purports to come up with a different point count and >pass this point count off as maybe more accurate than the historical >one. It may be more accurate but the Knight value looks too low. There >have always been particular materiel equation exceptions to the >historical point count and I looked at the experiment in that light. I >was interested in it from the chess perspective only. One particularly >gnawing exception to the historical point count is the 2R+N=2B+R >equation. This is supposed to be equal but of course it depends on >pawns. Of course there could be a different optimum point count for each >materiel equation on the board including pawns, and ultimately there is >an optimum different point count depending on the exact position. Of >course we are eventaully talking of the point count in general, because >point counts that depend on the position are useless and even point >counts that depend on materiel equation are impractical for OTB players. >Computers are a different story here. However for practical players, one >general point count or at least no more than one for each materiel >equation (not counting pawns) is a necessity for playing chess well. The >historical point count has held up fairly well. That is why I was >surprised that the experiment showed such a low value for the knight and >backed the accuracy up with another match based on search engines that >had positional algorithms as well. Don Beal's admission that the extra >match with historical point count against the experiment point count was >carried out with the same 4 ply depth limit, shows that the extra match >results are not meaningful for determining the accuracy of knights in >general. 4 plies is not enough to show the knights in their best light. >Rooks too can be undervalued at that limit and the results of the >experiment show that the rooks are undervalued against the historical >point count. 2 wrongs may make a right here but I would like to see >experiments of point count against point count at much deeper search >depths.
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