Author: Robert Hyatt
Date: 10:54:16 05/08/01
Go up one level in this thread
On May 08, 2001 at 13:21:07, Wayne Lowrance wrote: >On May 08, 2001 at 12:16:19, Robert Hyatt wrote: > >>On May 08, 2001 at 11:57:07, Larry Proffer wrote: >> >>>On May 08, 2001 at 11:43:29, Uri Blass wrote: >>> >>>>On May 08, 2001 at 10:58:01, Larry Proffer wrote: >>>> >>>>> >>>>>Thank you for your reply. I concur. >>>>> >>>>>What we do know is that Fritz and Junior are, to all intents and purposes >>>>>'equal', or very nearly 'equal'. >>>>> >>>>>If we need to find a winner, it makes *no* difference how many games we play. >>>>> >>>>>If we play one game, Fritz has a 50% chance, Junior a 50% chance. >>>>> >>>>>If we play one thousand games, Fritz has a 50% chance and Junior has a 50% >>>>>chance. >>>>> >>>>>Number of games is not relevant when they are so closely matched. >>>> >>>>I guess that the number of games is relevant and if the number of games is >>>>bigger the better learner is going to win and it means probably that Fritz is >>>>going to win after many games because Fritz has a bigger book so it is more easy >>>>for it to learn to go for lines that the opponent does not understand. >>>> >>>>Uri >>> >>>1. This, of course, opens up a lot of questions as to why machines were switched >>>after a few games. This would have killed Fritz's learn files. >> >>Why? Everything could have been moved easily. >> >> >>> >>>It is known that 'book-learning' can have bad effects, particularly after a >>>string of losses. The effect can be to push the program away from its usual >>>openings into even worse areas of the book. The desire, of course, is to hope >>>that it gets pushed away from the losses towards soemthign less bad, but, in >>>practice, it can be pushed into even worse regions from which there is no >>>escape. >> >> >>I don't know "where this is known" from.. If you lose a game with a specific >>opening, and you don't play it again, you won't lose that game again.. >> >Bob, I think that I have at times destroyed book lines for normal time controls >by playing blitz and bullet with losses. But these lines may be perfectly sound >for long time controls. I do not know this to be fact. Fritz took the book learning algorithm from Crafty, including the code that adjusts the learning value based on the rating of the opponent _and_ the search depth reached during the game. But in the case mentioned, there were _no_ blitz games of any kind played, just the qualifying games. > >Also another thought. Consider two opening main lines a.) Line (a) is in fact >better than line b). But against a better program line (a) loses, _not_ because >it is a bad line, it just lost. Maybe line (a) was playing a superior cpu, a >superior program and it lost. > >Opening line (b) is inferior to line (a) stipulated and will loose even worse >but now both of the lines, as I understand are Kaput. >> Not sure what you mean by "kaput" but not in Crafty, normally. IE a bad result out of book isn't enough to kill a line. It might remove the last couple of choices in that line, but not the entire line... unless you have a very tiny/ narrow book. Against a "better opponent" my book learning takes this into account, assuming the ratings are provided (this is automatic on a chess server)... >> >>> >>>Books are so large, and the pathways produced by learning so unpredictable, that >>>this effect is quite common. >> >>I have been doing "book learning" for 5 years now. I don't see this at all >>and I have a big book. >> >> >>> >>>So another question is why carry out a machine switch whose effect would have >>>been to kill the learnt data? >>> >>> >>>2. We know about learning in computer chess. Would you tell us if it (comp-comp >>>learning) has any relevance at all in 'finding the best opponent for Kramnik'. >>>Doesn't the luck involved with this bi-program learning process (remember, the >>>learning pathways are almost infinite - we don't know where they lead, and they >>>may make things worse) just add to the general fact that Fritz still has 50% >>>chance, and Junior still has 50% chance? >> >>Learning is part of the engine. In a match vs a human, a computer had _better_ >>have good learning skills or it will lose the same game over and over..
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