Author: Uri Blass
Date: 14:56:41 02/29/04
Go up one level in this thread
On February 29, 2004 at 17:20:33, Joshua Haglund wrote: >On February 29, 2004 at 16:33:46, Uri Blass wrote: > >>On February 29, 2004 at 16:29:15, Joshua Haglund wrote: >> >>>On February 29, 2004 at 12:48:06, Uri Blass wrote: >>> >>>>On February 29, 2004 at 12:20:03, Joshua Haglund wrote: >>>> >>>>>On February 29, 2004 at 03:20:30, Matthias Gemuh wrote: >>>>> >>>>>> >>>>>> >>>>>> >>>>>>My engine has a very unstable and unreliable search. >>>>>>Sometimes I think I implemented what you are proposing. >>>>>>My opinion is that the blindness introduced by such tricks would really hurt. >>>>>> >>>>>>/Matthias. >>>>> >>>>>yes! it wouldn't do the best search if it didn't reach great depth where f = 3; >>>>>If your engine searches deep try ply > 12. If it doesn't try ply 8, etc... :) >>>>> >>>>> >>>>>I have reason to believe a person will gain atleast 1 ply in the same amount of >>>>>searched time. >>>>> >>>>>example >>>>>time = 30; >>>>>ply 7 = 4 seconds. >>>>>ply 8 = 13 >>>>>no more plies reached. >>>>> >>>>>// with idea. >>>>>time = 30; >>>>>ply 7 = 1 second >>>>>ply 8 = 5 >>>>>ply 9 = 20 seconds >>>>> >>>>>Maybe this would be good for long time controls? Skip shallow and go to deeper >>>>>lines. >>>>> >>>>>Thanks for your reply, >>>>> >>>>>Joshua Haglund >>>> >>>>I can only say that I do not understand your idea. >>>> >>>>If you suggest to do selective search in the first plies then it seems to me a >>>>bad idea because you may miss important moves. >>>> >>>>It is more logical to be selective in the last plies and programs do it for >>>>example by qsearch but even then I do not see why do you use fixed number of >>>>moves and the number of moves that you search should be dependent on the >>>>position. >>>> >>>>prunning illogical moves is something important to do and programmers know it >>>>so it is not new information. >>>> >>>>Uri >>> >>>I thought about doing a selective search also... pretty much the same thing. >>> >>>If you skip time wasted looking at first several plies, it'll get to a greater >>>depth in less time to look for good moves. >>> >>>Thanks for your reply, >>> >>>Joshua Haglund >> >>selective search is good only in the last plies when the remaining depth is >>small. >> > >Here I do not follow you. What you are saying is you can only search so deep. >The only thing I consider last ply is the last ply searched. If we get to depth >90 i'm sure that isn't the last ply, unless mate occurs. the last ply means the last ply that I plan to search at that iteration. For example if you search at the 5th iteration 1.e4 e5 2.Nf3 Nc5 3.Bb5 then 3.Bb5 is the last ply. I see based on another post of you that you also think about pruning in the last 10 plies(in other words when the remaining depth is less than 10) but the problem is that a rule of having only 3 moves is usually too dangerous. > > > >>In this case you can relatively safely prune sacrifices because even if they are >>correct you usually do not have enough depth to see it. >> >>Uri > >This idea has nothing to do with specifically pruning sacrifices, but just >cutting the number of moves to look at so we get deep quicker, so we can start >looking for better lines at greater depth and start looking at all moves >possilbe instead of 3; not waisting time at shallow depth. If you want the idea of pruning(even when the remaining depth is small) to be productive you need usually to prune illogical moves and I see no way to do it when you let yourself to search only 3 moves. Uri
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