Author: Bas Hamstra
Date: 02:56:30 09/14/99
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Hi Frank, I meant "internal iterative deepening". So when the original rootalpha and rootbeta are still intact and there is no best move from the hashtable, you do a search to a shallow depth just to get a good move. My question is: what does it buy you exactly? So to see it won't cost you much (it only will do a couple of extra shallow searches), but does it do any good? Regards, Bas Hamstra. On September 14, 1999 at 05:10:39, Frank Schneider wrote: >Hi Bas, > >On September 14, 1999 at 04:07:18, Bas Hamstra wrote: > >>It seems I got PVS working. In comparison to simple alphabeta I get mixed >>results. I have seen positions where PVS does 20% less nodes than ab (starting >>position). However I have also seen (tactical) positions where PVS does do more >>nodes than ab. I am trying to find out how that's possible, but didn't have >>enough time. >> >>The impression is that pvs is just more sensitive to good moveordering than ab. >> >>I see that iterative deepening in Crafty. How important is it? >Iterative deepening is used in almost every program. The main effect is, >that by searching a position to depth n you get a very good moveordering >for the subsequent search to depth n+1. > >There is also an additional technique called 'internal iterative deepening'. >It is a little enhancement which can save time in some (rare) positions. > >Using iterative deepening is a must, internal iterative deepening is >nice to have. > >Frank > > > >> >> >>Regards, >>Bas Hamstra.
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