Author: blass uri
Date: 20:43:09 08/21/98
Go up one level in this thread
On August 21, 1998 at 16:31:42, Robert Hyatt wrote: >On August 21, 1998 at 10:54:04, blass uri wrote: > >> >>On August 21, 1998 at 10:33:44, Robert Hyatt wrote: >> >>>On August 21, 1998 at 09:56:10, blass uri wrote: >>> >>>> >>>>On August 21, 1998 at 08:59:25, Robert Hyatt wrote: >>>> >>>>>On August 21, 1998 at 07:58:21, Robert Henry Durrett wrote: >>>>> >>>>>>There have been quite a few threads this month dealing with test positions which >>>>>>test verious aspects of the software. >>>>>> >>>>>>But there is one question about the software which nobody seems to want to >>>>>>mention: Why do the chess engines have trouble with the initial position where >>>>>>no pieces have been moved yet? [Position at the start of all chess games] >>>>>> >>>>>>If the programs can be "tweaked" so that they play good openings, then all of >>>>>>the opening books will become unnecessary! >>>>>> >>>>>>Why not work on the "initial position" and get the programs to find the best >>>>>>move for that position? >>>>> >>>>>The primary reason this fails is you will get killed doing it. As a test, >>>>>try Crafty with either book=off, or book random 0, which means it will play >>>>>the exact same opening moves if you don't vary the time control. If you lose, >>>>>you can pick *any* move of yours you made, and replay the game to that point >>>>>and vary, knowing the program will walk down the same line again, since they >>>>>are "deterministic". You will eventually find a move that wins, and then it >>>>>is all over when word gets out, because everyone will play that move. >>>>You can use some learning and this is impossible to win by the same game. >>>> >>>>for example after a game you lost you can have a bad opinion against the moves >>>>you played(a panelty of 0.1 pawn against these moves is enough to change the >>>>first move and you cannot repeat the same game). >>>>another idea is to use singular extensions to the moves in the games that you >>>>lost. >>>>It is interesting to check what is the value of the opening book in ELO in the >>>>ICC if you use learning so you do not lose the same game twice. >>>> >>> >>>against *what* move? If a program doesn't have a book, and plays totally >>>on its own, as suggested above, then *what* move do you assume is bad >>>when your opponent plays the same first move again? Do you assume your >>>first move was the loser? The second? the 50th? >> >>I do not know so I decide to have an opinion against all the moves I played >>and I substract 0.1 pawn from the evaluation of the moves I played in the game I >>lost >>It can change the first move from 1.e4 to 1.d4 but not to 1.a4 and after some >>games I lose with white I play 1.e4 again because even with the -0.1 pawn >>it is better than alternatives without -0.1 pawns >>If the opponent play the same then I change the first move it is reasonable to >>change. >> >>Uri > >And you'd make the same mistake I made in the first verion of Crafty's learning, >too. :) > >IE it learned that *no* book moves were playable, because it only learned bad >things, and there is *no* move that someone can't beat you with... So it gets >*very* difficult to pull this off. That's why the current version also learns >"positive" things... > >Without the book, your idea would also cause problems, because the move at >move 20 might have been brilliant, while the move at move 30 was an outright >lemon. You penalize the brilliant move as well as the lemon, and play *worse* >moves everywhere in the game given another chance... I play worse moves only if the difference is less then 0.1 pawn and not everywhere. I do not think there is a big difference in the level I play in this case because 0.1 pawn is not much. > it would seem to me that >this would fail even worse than not learning, because this is "random" learning >with no idea of what was good or bad.. This is not worse than not learning because the worst thing is to lose all the time the same game. Uri
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