Author: Uri Blass
Date: 19:48:23 11/13/00
Go up one level in this thread
On November 13, 2000 at 15:26:15, Robert Hyatt wrote: >On November 13, 2000 at 13:58:49, Uri Blass wrote: > >>On November 13, 2000 at 11:55:08, Robert Hyatt wrote: >> >>>On November 12, 2000 at 15:10:43, Uri Blass wrote: >>> >>>>On November 12, 2000 at 13:25:15, Robert Hyatt wrote: >>>> >>>>>On November 12, 2000 at 12:48:14, Uri Blass wrote: >>>>> >>>>>>On November 12, 2000 at 11:05:30, Robert Hyatt wrote: >>>>>> >>>>>>>On November 12, 2000 at 10:54:42, Jeff Lischer wrote: >>>>>>> >>>>>>>>It seems if you correctly predict the opponent's move 100% of the time, this >>>>>>>>would correspond to doubling your available time (you would be thinking on your >>>>>>>>time as well as your opponent's time). If a doubling of speed results in an Elo >>>>>>>>improvement of 60-70 points, is this also the maximum benefit for permanent >>>>>>>>brain? With diminishing improvements at longer time controls, the benefit might >>>>>>>>be even less? >>>>>>>> >>>>>>>>If the above is correct, then what about the case where you correctly ponder >>>>>>>>only 60% of the time. This seems like a pretty typical value. Then is the >>>>>>>>benefit only about 40 Elo points? >>>>>>>> >>>>>>>>Are there any other approaches to permanent brain that might be more effective? >>>>>>>>At first I was wondering about simply searching on your opponent's time like you >>>>>>>>do on your turn -- using selective searching to focus on the best moves. But >>>>>>>>then I thought of another possibility. What about a different kind of searching? >>>>>>>>Maybe search using lots of knowledge during your opponents time trying to >>>>>>>>develop a plan? Or maybe do a fast selective search looking for killer tactical >>>>>>>>shots? >>>>>>>> >>>>>>>>Humans think differently on their time versus their opponent's time. Maybe >>>>>>>>computers would benefit from doing the same? I don't know enough about chess >>>>>>>>programming, however, to know how (or even _if_) the results of that "opponent's >>>>>>>>time search" could get passed to the "your time search". Would hash tables be >>>>>>>>sufficient? >>>>>>> >>>>>>> >>>>>>>This has been answered before... here is the quick version of the idea: >>>>>>> >>>>>>>let's take two different pondering algorithms: (1) present idea where we >>>>>>>assume that the best move from the last search is searched for the entire >>>>>>>time; (2) alternative where the best N moves are searched (less deeply of >>>>>>>course). >>>>>>> >>>>>>>case 1: target search time is 3 minutes. The opponent takes three minutes >>>>>>>to make his move. >>>>>> >>>>>>This assumption is not correct. >>>>>>The opponent(espacially in cases that the opponent is human) may use 30 minutes >>>>>>for one move and less time for the other moves) >>>>>> >>>>>>I believe that in this case it is better to stop searching the best move after >>>>>>part of this time and start to consider the response for the second best move. >>>>>> >>>>>>Uri >>>>> >>>>>The same thinking applies. I am _sure_ I am going to predict his move over >>>>>50% of the time. If he takes a long time, should I take a long time, or should >>>>>I do a bunch of three minute searches on different moves he might choose, and >>>>>after _his_ long think I play a move found after a 3 minute think? >>>>> >>>>>I think the current approach is best for _all_ circumstances... >>>> >>>>It is not clear. >>>> >>>>The benefit that you earn from another 3 minutes of search after you search for >>>>more time is smaller because of diminishing return from speed and in cases that >>>>you did not predict the move correctly in the first try you can earn the first 3 >>>>minutes that are more important. >>> >>>Note that I don't necessarily agree with the concept of "diminishing returns" >>>when it comes to search depth. >> >>It is clear that there is also diminishing return in search depth. >> >>The average search depth that you get from another minute is lower when you use >>more time so if you decide to start analyzing a reply for another move after 9 >>minutes of pondering you sacrifice less plies for the same target relative to >>the case that you do it after 3 minutes and it is logical to think that at some >>point the gain may be bigger than the sacrifice. >> >>Uri > > >I am not sure what you mean. When I ran the crafty goes deep tests, the >search depth was pretty linear. for every factor of 3x or so more time, it >went one more ply deeper. I didn't see any "wall" that it ran into. It does >help if you run it with a huge hash for huge searches. I assume the same branching factor(let assume it is 3). The point is that if you search the reply to the predicted move for 9 minutes instead of 12 minutes then you lose only (log(12/9))/log(3)) plies so you lose only (log(12/9)/log(3)) plies for another 3 minutes search that can help you in case that the opponent does not play the predicted move. If you search the reply for the predicted move for only 3 minutes you will lose (log(6/3)/log(3)) plies that is more plies for the same gain. I do not know when is the right point to start searching for reply for another move but it is logical to assume that at some point the gain is bigger than the loss. Uri
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