Author: Robert Hyatt
Date: 10:29:48 04/15/04
Go up one level in this thread
On April 14, 2004 at 14:38:57, Eric Oldre wrote: >Thanks to everyone who contributed to this thread, It's helped my understanding >a lot. > >I think I'll use the suggestion below and call queis(-INFINITY,INFINITY) for >each root node move to find the estimated score before starting iterative >deepening. > >Eric Oldre That works, except for certain "problem" positions as the q-search with that wide window can take forever. I've not seen it wreck things in normal games, however... > > >On April 14, 2004 at 12:28:54, Robert Hyatt wrote: > >>On April 14, 2004 at 03:32:17, Peter Fendrich wrote: >> >>>On April 14, 2004 at 02:21:41, Christophe Theron wrote: >>> >>>>On April 14, 2004 at 00:26:34, Eric Oldre wrote: >>>> >>>>>After you find the 1st "good" move don't you narrow the alpha beta window so >>>>>that you don't know how much worse the 2nd move is, only that it is not as good >>>>>as alpha? >>>>> >>>>>Or do you not narrow the window at the root node? that seems like it would >>>>>greatly expand your search tree. >>>>> >>>>>or am i missing something else? >>>>> >>>>> >>>>>On April 14, 2004 at 00:09:24, Robert Hyatt wrote: >>>>> >>>>>>Simple idea: >>>>>> >>>>>>a move is "easy" and can be made after using less than the planned time limit if >>>>>>and only if >>>>>> >>>>>>1. estimated score for first root move is way higher than the second move. IE >>>>>>say 2.00 better. >>>>>> >>>>>>2. This is a recapture. IE opponent just captured a piece of ours and we are >>>>>>recapturing on the same square. >>>>>> >>>>>>Other types of "easy" moves have higher risk to stop the search early... >>>>>> >>>>>> >>>>>>> >>>>>>>Thanks, >>>>>>>Eric Oldre (new chess programmer) >>>> >>>> >>>> >>>>I think that by "estimated score", Bob means the score returned by a SEE (Static >>>>Exchange Evaluator), not by a real search. >>> >>>I shouldn't tell what Bob means but I doubt this is right... >>>I wouldn't rely on a SEE for such decisions when the first few iterations will >>>give you a much more reliable score quite fast and you could use the score for >>>previous move in the game as a staring point. >>>If the score fulfills the conditions mentioned by Bob from the first iteration >>>and up to lets say 1/2 the total time alotted for that move then stop and make >>>the move. (Given that the time allocated for a move is just a function of >>>remaining time and number of moves left) >>>/Peter >>> >> >>I don't use SEE. I use a call to Quiesce() for each root move to get an >>approximate score for sorting them... >> >>It still isn't perfect, but it is not bad... >> >>>> >>>> >>>> >>>> Christophe
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