Author: Robert Hyatt
Date: 20:21:25 08/09/02
Go up one level in this thread
On August 09, 2002 at 12:58:00, Vincent Diepeveen wrote: >On August 09, 2002 at 00:50:04, Robert Hyatt wrote: > >for 5 men, uncompressed bittables 6GB or something similar. >Even my own bit less well compressing format it's well under 7 GB. > >if you compress that, it fits nearly in RAM... ...so you can probe >anywhere. also qsearch also leaves *everywhere*. Why would you want to? In the evaluation? If you make a capture, and then don't get a hit, and make another move, why probe _again_ as you will not get a hit there either. It is far better to probe where you transition into the egtbs after a capture. If you fit 'em all in RAM, then doing this in the q-search might be perfectly reasonable. For normal 7.5 gig compressed tables, probing in the q-search is a _bad_ idea... > >>On August 08, 2002 at 14:43:32, Alvaro Jose Povoa Cardoso wrote: >> >>>If I wanted to play with EGTBs with only win/loss/draw information and no >>>DTM/DTC information where would I place the probe code in the search routine? >>>Taking crafty as an example it has the TB probe code placed next to the hash >>>table probe code and if the current position is in a TB file it returns >>>immediately because is has perfect/complete information. But with 2bit/entry >>>EGTBs it just doesn't seem right to place the code there. It seems logic to me >>>to place the TB probe code in the evaluation function and if a leaf node is in a >>>2bit/entry TB file give it a bonus. Another possibility would be to place the TB >>>probe code before calling the qsearch. >>>Could someone tell me if I'm thinking correctly? >>> >> >> >>No. You should probe _exactly_ where I do. The only difference will be >>the "score". You won't be able to return a mate in N, so you will have >>to doctor the score to some value that says "mate in N where N is large and >>unknown." >> >>If you probe in the eval, you will probe a million times too often. You >>should probe when you drop into a 5 piece (or smaller) ending, which only >>happens infrequently and immediately after a capture only... If you do it >>at endpoints, you will get killed tactically because your search depth will >>drop off _several_ plies... >> >> >> >>>Best regards, >>>Alvaro Cardoso
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