Author: Sune Fischer
Date: 06:01:34 03/25/04
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On March 25, 2004 at 08:32:05, Fabien Letouzey wrote: >On March 25, 2004 at 08:11:08, Sune Fischer wrote: > >>On March 25, 2004 at 07:47:02, Fabien Letouzey wrote: >> >>>> >>>>So was I. You have only solved the problem along the PV. It _still_ exists >>>>along non-PV moves just as I explained... >>>> >>>>this has nothing to do with aspiration issues... >>> >>>Yes of course it does not fix all the problems, I should have stated >>>it. However I think I gain some "stability" (and a complete PV as a >>>side effect) at the cost of a 1-ply search (sometimes more) all along >>>the PV. For some reason, I did not consider turning hashing off >>>everywhere in the tree :) >>> >>>The tradeoff in my design is that null-window searches can do what >>>they want (forward prune, be inconsistent, etc ...), and the pv-node >>>search will try to accomodate with that. >>> >>>Fabien. > >>I recall having read about something similar, namely extending the PV to make >>sure the line is sound. > >>I believe the conclusion was that it didn't work so well, that the PV was no >>more important than the refutations and there was no a priori reason to be >>extending it. > >I have read this threat, but what I do is different. Technically it is different, but I what I was trying to getting at, is that the idea of using one type of search (more or less accurate) for PV nodes and another type of search for the others, might not work(?). It seems to me it could be a source of instability. No harm in trying of course, I alway say do the experiment! :) >There is no extra depth anywhere. >My 1-ply thing is because I don't use hash-table values at PV nodes, so Fruit >needs a 1-ply search to find it again (and 1-ply search at the PV node son etc >...). "find it again"? Do you mean the PV move? Even if you don't want to cut on a pv you could still get the hash move to try. Although I don't see a reason not to cut if the HT says cutting is fine. >At each PV node (usually a single line), all siblings are searched. I'm a bit fuzzy on the siblings, a PV sibling? I don't think I know what that is. :) -S. >Fabien.
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