Author: Robert Hyatt
Date: 19:57:21 03/18/03
Go up one level in this thread
On March 18, 2003 at 16:33:29, Matthew White wrote: >On March 18, 2003 at 16:24:32, Robert Hyatt wrote: > >>On March 18, 2003 at 16:04:21, Matthew White wrote: >> >>>On March 18, 2003 at 09:59:00, Robert Hyatt wrote: >>> >>>>On March 18, 2003 at 04:18:05, Ed Schröder wrote: >>>> >>>>>On March 17, 2003 at 21:54:36, Nathan Thom wrote: >>>>> >>>>>>Im having troubles trying to figure out what to do with my search results when a >>>>>>timeout occurs. eg I could have searched 10 plies fully, and am part way through >>>>>>the 11th ply when time runs out. >>>>>> >>>>>>The simplest thing to do is ditch all results from the last incomplete search >>>>>>and just go with what you had after 10 plies. But this seems a big waste. >>>>>> >>>>>>Thoughts? >>>>> >>>>>Nathan, >>>>> >>>>>It's quite simple, just check the "time_is_up" condition after your "undo_move" >>>>>call and jump to the place where you climb back one ply in the tree (as if there >>>>>are no more moves to search on the current ply). >>>>> >>>>>My best, >>>>> >>>>>Ed >>>> >>>> >>>>This can be a fatal error. You are at ply=N and have 10 legal moves to search. >>>>The first is horrible, but the second wins everything. If you quit after >>>>searching the first move and return that score, the previous ply may well like >>>>the move it tried, and since it has now searched every move, it backs the >>>>score up. And so forth. But when the game really enters this path, the >>>>first move is not actually played by your opponent, he plays the second, and >>>>the roof falls in. >>>> >>>>You have to _not_ back up things from below the root, once you have decided that >>>>time is up. >>> >>>What if you finished ply N with a lazy eval instead of the full eval. Would that >>>solve the problem? >>> >>>Matt >> >> >>I don't see how. I use lazy eval all the time... >> >>the point is that when time runs out, you can't just stop and back things up as >>you >>have not finished the current root sub-tree you are working on, and the scores >>are >>therefore worthless for this root branch. But anything else already completed >>is >>certainly good. >I see what you mean. I was just wondering if giving the rest of that ply a quick >"once-over" would give sufficient information to allow the score to stay in the >tree. It would be hard. IE how do you compare a move searched normally to a move "glanced over quickly" if you want to choose between them?
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