Author: Stuart Cracraft
Date: 19:06:47 09/06/04
Go up one level in this thread
On September 06, 2004 at 18:37:47, Robert Hyatt wrote: >On September 06, 2004 at 13:14:36, Stuart Cracraft wrote: > >>On September 06, 2004 at 11:23:23, Richard Pijl wrote: >> >>>On September 06, 2004 at 10:48:00, Stuart Cracraft wrote: >>> >>>>On September 06, 2004 at 04:47:12, Alessandro Scotti wrote: >>>> >>>>>On September 05, 2004 at 22:12:35, Stuart Cracraft wrote: >>>>> >>>>>>I walk the PV until there is no further position. No limit. This can then >>>>>>either be left in the hash table if you don't clear between searches >>>>>>but like Bob, you should keep the PV entries and restore them in the >>>>>>hash table before the next search whether or not you table-clear due to >>>>>>potential changes. >>>>>> >>>>>>I don't do this. It's a simple fix. I don't know why I've delayed putting >>>>>>it in. >>>>> >>>>>I don't either. But since I get my PV from the hash table, it's already there. >>>> >>>>Mine is already in there as well so I don't see why Bob said to >>>>store it in the hash table after the last iteration unless Crafty uses >>>>some different method to record the PV and has to store it in the hash >>>>table prior to the next iteration. Why wouldn't it be in there already? >>>>Does Crafty clear the hash table between moves? >>> >>>Reinserting (from a PV array) makes sure that the whole PV is in there for the >>>next search. The PV positions could have been overwritten by other positions. >>>Richard. >> >>But if you got it originally from the hash table in the first place at the >>end of the last iteration, then they may already have been overwritten. >>You would have to use an alternate method like triangular array to >>store them, away from hash, then access that array and fill hash from >>it prior to new iteration. > > >That is the point. _I_ don't get it from the hash table in the first place, but >I do want to make sure it is there at the start of the next iteration so that my >move ordering (which always searches hash move first) will be correct. > >If you get it from the hash, you get bad/short PVs regularly. No need to >re-insert them since what is already there is all you have anyway. But it does >lead to PV problems to do it from the hash... Then I need to borrow Bruce's code from his site some day and implement that.
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