Author: Robert Hyatt
Date: 21:08:41 01/07/99
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On January 07, 1999 at 23:53:36, James Robertson wrote: >Hi, >I have just started implementing hash tables into my program. Already, I have >run into *major* problems. Most of them I can probably fix on my own, but a few >I need help with: > >Problem #1 Out of a search of maybe 700k nodes (counting q-nodes), I will only >get maybe 6k positions that the program attempts to enter into the tables! What >is a reasonable number of storage attempts for a program during a search of that >length? > something is wrong. Whenever you exit from your recursive search call, you should do a HashStore() operation... not just when you fail high or back up a good score, but also when you simply back up alpha because all moves were refuted... >Problem #2 I get tremendously few hits, but that is probably because of problem >#1. > >I figured these would be the best solutions to my problems: > >Solution #1 Someone posting a simple alpha-beta function somewhere where so I >can see where what hash stuff (probes, etc.) goes where. > >Solution #2 Someone also explaining the above code. > >Solution #3 Someone speculating on what I might be doing wrong (less crucial). > >Please help!! >James look at _every_ return from your search function. If there is any path out of search, except at the top where you detect a repetition or do a hash lookup and get a hit, you need to fix that so that you always store the search result before exiting.
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