Author: KarinsDad
Date: 10:27:33 07/26/00
Go up one level in this thread
On July 26, 2000 at 11:45:30, John Coffey wrote: [snip] > >My concern is that attempts to choose from a random list of moves will produce >the same kind of effect that we see with some programs - where they will play >really well on some moves but do something completely stupid on another. I have >had games with Fritz (on a lower rating) where it clearly could have won a king >and pawn endgame but started making random king moves and lost. It was much >too obvious that the computer was throwing the game. It seemed bad to struggle >so hard against the computer the whole game only to have the computer completely >botch it. > >Now maybe the idea of playing well on some moves and bad on others is how 1200 >players actually play. I prefer to have an consistant standard that I am >playing against - so even if the program doesn't make one move blunders (unless >we set the nodes really low) I am going to get a more consistent feel throughout >the whole game. I feel that this is a better training method for >me trying to improve my game. > >It is hard to define how many bad blunders a 1200 should make. I have played >1200's in tournament who drop pieces. On the other hand, I just lost to an >1100 in a tournament who didn't seem to make any mistakes the whole game. (I am >an A player.) > >Yes, I wish for the ability to set the think time to fractions of seconds per >move. > >John Coffey You must not have carefully read what I wrote. I never said to play random moves. I said to play one of the best x moves, probably based on a bell curve decision, and probably limiting depth for the lower settings. At setting 1200, the program might search the best 7 moves at a ply 4 depth, and the position scores result in: 1) +0.2 9% 2) +0.19 12% 3) +0.14 16% 4) -0.12 26% 5) -0.74 16% 6) -1.15 12% 7) -6.74 9% as the best 7 moves with respective probabilities of being played. So, the program will often play a somewhat ok move in this position and occassionally play move #7. However, the ply was only 4, so move #7 might actually be the best move on the board. At setting 1600, the program might search the best 5 moves at a ply 6 depth, and the position scores result in: 3) +0.31 8% 2) +0.26 23% 1) +0.19 38% 6) +0.07 23% 5) -0.21 8% as the best 5 moves with respective probabilities of being played. You'll note that the order and scores of the moves has changed due to searching deeper ply. Additionally, there is a lesser chance of playing an inferior move since only the top 5 moves are examined. At setting 1650, the program might use the same algorithm as 1600, but shift the probabilities for a given move up: 3) +0.31 11% 2) +0.26 37% 1) +0.19 31% 6) +0.07 16% 5) -0.21 5% Yes, there is randomness in this approach, but it is not linear, nor is it based off random extremely bad moves. Additionally, the scores of the x moves could play a part in the percentages as well. KarinsDad :)
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