Author: Uri Blass
Date: 09:04:03 11/11/02
Go up one level in this thread
On November 11, 2002 at 10:28:33, Robert Hyatt wrote: >On November 11, 2002 at 01:10:23, Uri Blass wrote: > >>On November 10, 2002 at 23:53:19, Robert Hyatt wrote: >> >>>On November 10, 2002 at 22:38:03, Jeremiah Penery wrote: >>> >>>>On November 10, 2002 at 21:29:43, Robert Hyatt wrote: >>>> >>>>>On November 10, 2002 at 21:15:07, Jim Bumgardner wrote: >>>>> >>>>>>Which of these strategies for "think on opponent's time" makes more sense? >>>>>> >>>>>>A) To only search the top-move from the principle variation. If >>>>>>the opponent makes that move, continue searching, otherwise reset and >>>>>>search again. >>>>> >>>>>This is the _only_ way to do it. I've explained this many times, but it >>>>>is probably time to go it again... >>>> >>>>For the general case. But it shouldn't be hard to find situations where it's >>>>very easy to tell the ponder move is probably wrong. In those cases, it's >>>>obvious, IMO, that switching to a different ponder move would help. >>>> >>>>One possible scenario is when the ponder move keeps failing high - either the >>>>ponder move is wrong, or you ponder some other move and you'll find the >>>>fail-highs again anyway if they play the original ponder move. Otherwise, >>>>you'll have a better chance of pondering on a better move. You could always >>>>save the result of the first ponder search just in case. >>> >>> >>>That is a good point of course. If you get the fail high _before_ using the >>>"target time" then you can safely switch to pondering something else, knowing >>>you will have time to find the "fail high" again, if the opponent makes the >>>expected move. >>> >>>The bad side might be that you don't fail high until you are beyond your target >>>time, so that if you start pondering something else, you might not be able to >>>find the fail high for real if the opponent actually makes that move... >> >>You assume here that you are going to forget the fail high. >> >>You can rememeber the move that you want to play against the expected move in >>case of fail high and continue to search other moves and when the opponent plays >>the expected move you can play the move that you remember in 0 seconds. > >Yes, although I am trying to adhere to the KISS principle here. The above >would work well, but it would introduce additional complexity and the >opportunity for bugs. But it might be worth it too... > >> >>I also believe that the best strategy is not to ponder only on one move but to >>have a lot of threads(for every legal move of the opponent a different thread) >>and to give different priority for different moves. > >How about some math to show how the above is going to be better than pondering >one move that is correct over 50% of the time. I don't see any way to improve >except in special cases such as a terrible fail-high that lets you know your >opponent probably won't play that move... I admit that there is not a big improvement but if you want some math then here is is: What is better? Case A:You ponder the expected move 60% of the cases and ponder another move in 40% of the cases case B:In the same 60% of the cases you use 90% of the time for the expected move. In the rest of the 40% of the cases you use 30% of the time for the move that is going to be played. 0.6*0.9+0.4*0.3=0.66>0.6 Uri
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