Author: blass uri
Date: 00:58:27 04/03/00
Go up one level in this thread
It cannot find one of them to be best because it does not anlyze the second best option to a bigger depth and the reason it used less time for the second best option is that programs use the alpha beta algoritam. I think that their algoritam can be improved and I think that having no knowledge about the second best move is not a good idea because you can use this information to know which lines to extend more but having more than one option is a bad idea if you do not develop another program. alpha beta algoritam explanation: The idea of the alpha beta is not to analyze lines when it is clear that white did illogical moves(evaluation<alpha) and not to analyze lines that it is clear that black did illogical moves(evaluation>beta). I will give an example for the alpha beta algoritam to explain what programs do: suppose that the program caluclated 1.d4 and found evelauation of +0.1 pawn for white and also calculated 1.e4 f5 and found an evaluation of +1 for white and now calculates 1.e4 e5 Nf3 If the evaluation of 1.e4 e5 2.Nf3 is bigger than +1 you know that f5 is better than e5(black did an illogical move) and you do not have to calculate other options for white instead of 2.Nf3 because they will not change the score of 1.e4 that is not bigger than +1 because of 1...f5 If the evaluation of 1.e4 e5 2.Nf3 Nc6 is smaller than +0.1 then 1.d4 is better than 1.e4 e5 2.Nf3 so an exact value of 1.e4 e5 2.Nf3 is not important (because you know that white did illogical move in this line(because d4 is better) and you go to analyze lines like 1.e4 e5 2.Nc3 and you save time by avoiding to analyze lines like 1.e4 e5 2.Nf3 Nf6 When you calculate the 2 best options then you have to know the exact score of 1.e4 when 1.d4 is best and you cannot save time by avoiding to analyze some lines when white does illogical moves. I hope my explanation is clear. Uri
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