Author: Uri Blass
Date: 20:03:19 07/27/04
Go up one level in this thread
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
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