Author: Ricardo Gibert
Date: 23:30:21 11/18/00
Go up one level in this thread
On November 19, 2000 at 01:34:14, Uri Blass wrote: >On November 19, 2000 at 01:15:22, Ricardo Gibert wrote: > >>On November 18, 2000 at 22:13:35, Peter Kappler wrote: >> >>>On November 18, 2000 at 21:23:54, Ricardo Gibert wrote: >>> >>>>On November 18, 2000 at 12:37:20, Amir Ban wrote: >>>> >>>>>On November 18, 2000 at 06:03:39, Graham Laight wrote: >>>>> >>>>>>On November 17, 2000 at 19:24:23, Amir Ban wrote: >>>>>> >>>>>>> >>>>>>>If your criterion of knowledge is based on accuracy of evaluation then I >>>>>>>respectfully apply for membership in the exclusive "knowledge based" club (and >>>>>>>IMO some members don't belong there). >>>>>>> >>>>>>>BTW, accuracy of evaluation is the best criterion for being knowledgable that >>>>>>>I'm aware of. I've posted here in the past that, to start with, we don't have a >>>>>>>real definition of what good evaluation means. This is the focus of my work with >>>>>>>Junior for more than a year. >>>>>> >>>>>>IMHO, a truly accurate evaluation of a position would yield one of the following >>>>>>3 ordinal values: >>>>>> >>>>>>Win >>>>>>Draw >>>>>>Lose >>>>>> >>>>>>-g >>>>>> >>>>>>>Amir >>>>> >>>>>I can easily fake evaluation that gives only those values. I suppose that you >>>>>mean that the values should be true values. How do you propose to do that ? If I >>>>>have an eval that gives absolutely correct values 60% of the time (and the rest >>>>>wrong), do you expect my program to be weak or strong ? If I get 70% right, am I >>>>>necessarily stronger ? >>>>> >>>>>The question is, given two evaluation functions, to decide which is more >>>>>accurate. >>>>> >>>>>This is a good question. Your answer does not seem to lead anywhere. >>>>> >>>>>Amir >>>> >>>>With 100% correct evaluations of just win, lose or draw, can a program mate in K >>>>+ R vs K? I think it will just wander around unless mate happens to fall within >>>>the program search horizon. Yes? >>> >>>Yep, it would wander around until it lucked into a mate or until the "threat" of >>>a draw by the 50-move rule forced it to play a mating line. >>> >>>--Peter >> >>The 50 move rule may or may not force it to play a mating line. Example: >> >>Lets say the program has played 40 moves without pawn move or capture and is >>able to search only 20 ply. At that point, it may find that a draw due to the >>move rule is a problem, but may not be able to anything about it, since the >>position may actually require more than 10 moves (20 ply) to mate. > >If the program has accurate evaluation the 50 move rule is not relevant because >it will never go to a position that is drawn by the 50 move rule because the >evaluation will not let it to do it because it is going to tell it that it is a >draw(the same position with different history of the game should be evaluated as >a win but accurate evaluation should consider also the history of the game). > >If the program has accurate evaluation of draw,win,loss one ply search is enough >to win won positions. > >Uri It would be a pretty amazing eval that detects 50-move draws in the eval rather than in the search. I think the normal assumption is that it is detected in the search. I think that is quite clear that is the operative assumption in this thread.
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