Author: Robert Hyatt
Date: 17:33:27 10/20/98
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On October 20, 1998 at 08:20:53, Ernst A. Heinz wrote: >On October 20, 1998 at 08:08:23, Robert Hyatt wrote: >> >>Quite easy. With alpha/beta the only "order" we have is (1) best move and >>(2) rest of moves. There is no "order" to the moves other than one move is >>better than all the rest. No idea how much better, no idea where the other >>moves rank with respect to each other... > >In order to avoid wide-spread confusion, I would like to add that Bob's above >statement implicitly assumes "alpha-beta" to mean "PVS/NegaScout" as employed >by most chess programs. > >Pure alpha-beta without null-window searches and eager resolution of any >fail-high/fail-low situations can of course calculate accurate search scores >of all moves. But it would be horribly inefficient as compared to PVS (yet >still much better than naive minimax). > >=Ernst= No "pure" alpha/beta can do this. But if, at the root, you simply reset alpha/beta after each root move, you get a score whether it be from a PVS search a negascout search or a traditional alpha beta (I don't see what null- move has to do with this issue at all). But the math is gross... and you will lose 3-4 plies probably...
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