Author: Robert Hyatt
Date: 12:03:30 07/27/04
Go up one level in this thread
On July 27, 2004 at 14:43:06, Sune Fischer wrote: >On July 27, 2004 at 13:33:40, Robert Hyatt wrote: > >>On July 27, 2004 at 09:42:46, Sune Fischer wrote: >> >>>On July 27, 2004 at 09:33:13, Anthony Cozzie 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. >>>>> >>>>>-S. >>>> >>>>It seems you have 3 options here: >>>> >>>>Optimism: Hope that a move you haven't searched yet will fail high; terminate >>>>after searching all moves. >>>> >>>>Pessimism: Make sure that the move you want to play won't fail low: terminate >>>>after searching the first move. >>>> >>>>Don't Care: Just exit whenever time runs out ;) >>> >>>I think you have more choices, e.g. search the next ply, when time is about to >>>run out, with a null window around the fail-low bound. >> >>I don't think any of that is reasonable. I have seen searches where the first >>move takes 1 second to resolve a true score. I have seen searches where the >>first move will talk almost forever to resolve the score. KISS is a good idea >>here, IMHO. > >...which is why you shouldn't try and resolve the score. :) How is that KISS? IE I +normally+ try to resolve the score, so why change what is the normal case??? For a special case that is not particulary significant. > >>> >>>Just to assert as quickly as possible that it doesn't fail horribly low. >>> >>>Little sense in trying to resolve an exact score for the next ply if you only >>>15% time left. >> >> >>Often that is more than enough time to resolve the score. > >I think 15% is rarely enough time. 100 seconds per move. 15% is 15 seconds. For the first N iterations that is more than enough time. How to accurately predict when you are starting the _last_ iteration? > >If the whole last ply took 70% and the first move on the last ply took 60%, then >you can probably expect to use about twice that, i.e. 120% time, to resolve the >score on the first move. > >That's pretty hopeless unless something dramatic happens. > >-S. Try fine 70 for a quick counter-example...
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