Author: Matthew White
Date: 13:33:29 03/18/03
Go up one level in this thread
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.
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