Author: Robert Hyatt
Date: 07:54:29 07/28/04
Go up one level in this thread
On July 27, 2004 at 23:03:19, Uri Blass wrote: >On July 27, 2004 at 22:44:31, Robert Hyatt wrote: > >>On July 27, 2004 at 19:53:32, Uri Blass wrote: >> >>>On July 27, 2004 at 19:37:13, Robert Hyatt wrote: >>> >>>>On July 27, 2004 at 18:53:29, Uri Blass wrote: >>>> >>>>>On July 27, 2004 at 18:10:11, Robert Hyatt wrote: >>>>> >>>>>>On July 27, 2004 at 16:53:17, Uri Blass wrote: >>>>>> >>>>>>>On July 27, 2004 at 16:01:09, Robert Hyatt wrote: >>>>>>> >>>>>>>>On July 27, 2004 at 15:25:50, Uri Blass wrote: >>>>>>>> >>>>>>>>>On July 27, 2004 at 13:26:54, Robert Hyatt wrote: >>>>>>>>> >>>>>>>>>>On July 27, 2004 at 12:42:42, Uri Blass wrote: >>>>>>>>>> >>>>>>>>>>>On July 27, 2004 at 11:11:10, Robert Hyatt wrote: >>>>>>>>>>> >>>>>>>>>>>>On July 27, 2004 at 03:18:50, Sune Fischer wrote: >>>>>>>>>>>> >>>>>>>>>>>>>On July 25, 2004 at 22:01:31, Robert Hyatt wrote: >>>>>>>>>>>>> >>>>>>>>>>>>>>Bad idea. Start the next iteration even if you don't think you will have time >>>>>>>>>>>>>>to finish it. You might fail low. Wouldn't that be nice to know? :) >>>>>>>>>>>>> >>>>>>>>>>>>>This may or may not be a good idea. >>>>>>>>>>>>> >>>>>>>>>>>>>I think if it is a good idea, then you should always try and search the next >>>>>>>>>>>>>iteration for a short time to see if you get a quick fail-low. >>>>>>>>>>>>> >>>>>>>>>>>>>On the other hand, if it is a bad idea it is better to save the time that will >>>>>>>>>>>>>probably be wasted anyway. >>>>>>>>>>>>> >>>>>>>>>>>>>From what I can tell you propose to do a mixture, i.e. to use extra time if the >>>>>>>>>>>>>time manager tells you to? >>>>>>>>>>>>> >>>>>>>>>>>>>I really doubt this is the best way, because it will be extremely random when >>>>>>>>>>>>>you get to begin the next ply. >>>>>>>>>>>> >>>>>>>>>>>>No idea what that means. I set a target time. If I have not used that much >>>>>>>>>>>>time, I keep searching. Whether that means starting a new iteration or >>>>>>>>>>>>continuing on the current iteration. >>>>>>>>>>>> >>>>>>>>>>>>When the target time is reached, I set a flag that says "do not search another >>>>>>>>>>>>root move, but don't stop until either the current root move has been searched >>>>>>>>>>>>or 2x the time limit has been used." This does not apply if the root move being >>>>>>>>>>>>searched is the first one in the list... >>>>>>>>>>> >>>>>>>>>>>Basically there are 2 cases to consider. >>>>>>>>>>>case 1:you did not expect the opponent move correctly. >>>>>>>>>>>case 2:You expected the opponent move correctly. >>>>>>>>>> >>>>>>>>>>I completely ignore this. My only purpose for "pondering" is to save time so >>>>>>>>>>that I have more later when I need it. >>>>>>>>> >>>>>>>>>I think that it is wrong to ignore it because the situation is not the same. >>>>>>>>> >>>>>>>>>suppose that you have 2 minutes to finish the game when the opponent played fast >>>>>>>>>in previous moves and have 20 minutes to finish the game >>>>>>>>> >>>>>>>>>Suppose also that the opponent used 2 minutes for the last move. >>>>>>>>> >>>>>>>>>If you pondered the correct move you can use more than 2 minutes without losing >>>>>>>>>on time(you count in that case also the time that you used in the opponent time >>>>>>>>>otherwise you can never reply immediatly) and there may be cases when you want >>>>>>>>>to do it(for example after a big fail low when you hope to find a better move). >>>>>>>> >>>>>>>>I don't understand. When I am "pondering" I have no "time limit" to deal with. >>>>>>>>The time limit is set when my opponent actually moves and my clock starts. I >>>>>>>>will generally "move instantly" in such a case where I have a small time target >>>>>>>>but used a lot of time waiting on my opponent... >>>>>>> >>>>>>>Suppose that it is game in 30 minutes without increasment to do things more >>>>>>>simple. >>>>>>> >>>>>>>If I understand correctly you simply use the following factors to decide if to >>>>>>>play immediatly. >>>>>>> >>>>>>>1)target time that is based on the time that you have to finish the game. >>>>>> >>>>>>Correct... >>>>>> >>>>>>>2)time used that is based on the time that you started the search(if you >>>>>>>pondered correctly it is a positive number and if you pondered wrong it is 0) >>>>>> >>>>>>No. It is zero for either case. IE my "ponder start time" is the instant I >>>>>>start pondering. My non-ponder-start-time is the instant I start searching. My >>>>>>time limit will either be ponder-start-time + time limit, or >>>>>>non-ponder-start-time + time limit. IE when I ponder and use my target, I might >>>>>>actually use zero clock time. With a non-ponder search I always burn time off >>>>>>of my clock. >>>>>> >>>>>>But here is an easier-to-visualize explanation: >>>>>> >>>>>>I set a target time of 100 seconds and start pondering. My opponent makes a >>>>>>different move. I re-start the search from the right position, and I'll burn >>>>>>100 seconds off my clock, then make the move. >>>>>> >>>>>>I set a target time of 100 seconds and start pondering. My opponent makes the >>>>>>right move after 150 seconds. Since I have searched for > my target time, I >>>>>>move instantly and save that 100 seconds to use later if needed. >>>>>> >>>>>>I set a target time of 100 seconds and start pondering. My opponent makes the >>>>>>right move after 50 seconds. I continue searching for another 50 seconds to use >>>>>>my total 100 second time limit, but I only burn 50 seconds off the real chess >>>>>>clock. I save the other 50 seconds for use when needed later in the game. >>>>> >>>>>I understand. >>>>>It simply seems to me not the best decision and I think that it is better to >>>>>decide about the target time after the opponent plays it's move. >>>> >>>>I don't see the difference. In one case, I "assume" that my opponent makes the >>>>predicted move and set a time limit. In the other case he actually makes a move >>>>and I set a time limit. Are you saying you might choose a different time limit >>>>depending on whether he plays the predicted move or not? >>>> >>>>I can't really say whether that would be reasonable or not. Perhaps if I >>>>predict correctly I either (a) understand things well enough that less time >>>>would be safe, or (b) don't have a clue and am walking into some deep error that >>>>I need more time to see. >>>> >>>> >>>> >>>>> >>>>>The reason is that if you pondered the correct move you simply have more time >>>>>for other moves and not use part of it for the next move seems to me not correct >>>>>decision. >>>> >>>> >>>>I don't quite see how I could do that. I suppose I could set the ponder time >>>>limit such that I assume I am correct, but how could I guess how long my >>>>opponent would take to search that move and then play it? I have no idea what >>>>his time limit is set to. It could be short for an easy move. His "best" move >>>>could fail low and make him take a long time. IE I see no reasonable way to >>>>guess how much time I will save until I actually save it (if I do). >>>> >>>> >>>> >>>> >>>>> >>>>>The problem may be more important in time control of x minutes/y moves >>>>> >>>>> >>>>>Let look in the case of 40 minutes/40 moves(does not happen in ICC but happen in >>>>>tournaments that people play). >>>>> >>>>>Suppose that Crafty is at move 39 and has 2 minute on the clock for move 39-40. >>>>>suppose that the target time is the average time that you have for a move. >>>>>Suppose that you decide about target time of 1 minute and the opponent use >>>>>exactly 1 minute to play so you respond immediatly. >>>>> >>>>>Now at move 40 your target time is bigger and is 2 minutes. >>>>>A better decision seems to me to increase the target time for move 39 to 1.5 >>>>>minutes and you can use 1.5 minutes both for move 39 and for move 40 that seems >>>>>more logical to me than 1 minute for move 39 and 2 minutes for move 40. >>>>> >>>>>Uri >>>> >>>>I can see that failing easily. I set the target time at move 39 to 1.5 minutes. >>>> My opponent moves instantly and plays the predicted move. I'm now stuck with >>>>burning 1.5 minutes leaving 30 seconds for the last move... >>> >>>The idea is that you set the target time only after the opponent play. >>> >>>If the opponent played not the predicted move then your target time is 1 minute. >>>If the opponent played the predicted move your target time is dependent on the >>>time that the opponent used. >>> >>>If the opponent used 1 minute then your target time is 1.5 minutes but if the >>>opponent replied immediatly it is still 1 minute. >>> >> >>OK. that is easy to do. Early CB versions did that very thing. But later we >>chose to save the time. IE what is the reason to search deeper only on moves >>where you predict correctly? Those are the ones that are probably most >>accurately evaluated already... So we chose to go to the "pure target time" and >>search all moves for about the same time (excluding long ponder thinks when the >>opponent goes for a long time of course). I think that overall it is better to >>be fairly uniform, rather than randomly searching some positions more deeply, >>without any sort of clue that more searching is needed (fail low, etc.) > >I think that my suggestion does the time of search more uniform. >In the case that you did not predict the right move you can search 1 minute both >for move 39 and move 40. > >In the case that you predicted the right move correctly and the opponent used 1 >minute you can search 1.5 minutes for move 39 and 1.5 minutes for move 40. > >Uri The danger is non-uniform depth. If you vary the time, you also vary the depth. That leads to a particular playing problem I don't want to deal with. The more consistent things are, the more consistent the engine plays...
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