Author: James Robertson
Date: 20:45:47 10/24/99
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On October 24, 1999 at 22:54:00, William Bryant wrote: >On October 24, 1999 at 12:55:22, James Robertson wrote: > >>r4q1k/p2bR1rp/2p2Q1N/5p2/5p2/2P5/PP3PPP/R5K1 w - - bm Rf7; id WAC008; >> >>My program has always solved WAC 8 easily. But last night I noticed the latest >>version chose Nf7+ instead of Rf7. I looked at the position with Crafty 16.18, >>and it gives mate in 7 after Rf7. After Nf7+, Crafty gives mate in 10 on ply 12, >>so this value may not be trustworthy. >> >>Can anyone look at the position and find out how far Nf7+ really is from mate? >> >>James > > >Jumping on this thread late, > >James, mate positions in the hash table can be tricky. My first problems were >with the program never choosing the shortest path to mate. Bruce is an advocate >of only storing bounds -not- distance to mate in the hash table. Bob, just the >opposite. > >If you were solving this before your latest 'change'. See if the change affects >your hash table and therefore starts leading you for a longer mate. > >William >wbryant@ix.netcom.com I generally test WAC with 5 seconds per position. On my P233, nobody finds this mate in that amount of time. :) James
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