Author: Dave Gomboc
Date: 21:03:46 02/08/00
Go up one level in this thread
On February 08, 2000 at 23:57:54, Robert Hyatt wrote: >On February 08, 2000 at 23:21:53, Peter W. Gillgasch wrote: > >>On February 08, 2000 at 23:17:08, Dann Corbit wrote: >> >>>On February 08, 2000 at 22:13:58, Peter W. Gillgasch wrote: >>> >>>>On February 08, 2000 at 20:11:50, Dann Corbit wrote: >>>> >>>>>2bnN1k1/6P1/4p3/1P2N1P1/3K4/8/8/8 w - - >>>> >>>>Including producing a full blown log file with an awful lot of >>>>statistics it took 2 seconds on my 60 mhz PowerPC601 machine. >>>>Iteration 7, 43914 nodes, minimal hashtable (128 K entries). >>>>This time includes clearing the hash table. >>>> >>>>Without the hash table it took 3 seconds, iteration 7, 77162 >>>>nodes. I believe that things like these can be solved easily >>>>much faster with better selectivity. >>>> >>>>Is there anything special about that problem ? >>> >>>Nothing that I can see. Crafty finds the right move in less than two seconds, >>>but fails to see the mate for 6 minutes. Looks like a bug or ??? >> >>Jesus Christ ! Looks like Bob will have to work overtime. I did >>notice that one log shows something like several million nodes >>but I did not notice the time. Looks like a bug to me or maybe >>some of his pruning stuff fouls it up big time ?! >> >>-- Peter > > >It doesn't appear to be a bug.. just that on the fail high, some mates that >were pruned suddenly become "ok". And move ordering just happens to follow >an incredibly deep series of checks first. IE it finds a mate in 15 or so >very quickly then tries to improve. But in doing so, it searches a _bunch_ >of stuff. Just runaway extensions, mainly. Do you cap your maximum extension bonus to 1 ply per ... well, ply? :) Dave
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