Author: Omid David
Date: 15:10:41 08/30/02
Go up one level in this thread
On August 30, 2002 at 17:24:34, Andreas Herrmann wrote: >On August 30, 2002 at 14:33:08, Omid David wrote: > >>On August 30, 2002 at 14:27:53, Andreas Herrmann wrote: >> >>>On August 30, 2002 at 09:56:21, Omid David wrote: >>> >>>>On August 29, 2002 at 23:03:43, Dann Corbit wrote: >>>> >>>>>On August 29, 2002 at 22:50:53, Brian Richardson wrote: >>>>>[snip] >>>>>>Is move sorting turned off in Yace, GLC and Gnu for the depth = 6 searchs? >>>>> >>>>>Pretty irrelevant since all of them show a branching factor between 2 and 3 for >>>>>the opening position. >>>>> >>>>>The program described by the OP had a branching factor of 6-8, IIRC. >>>>> >>>>>IOW, something is clearly amiss. >>>>> >>>>>I wonder how often the OP finds the requested position in the hash table. >>>>>Usually, hash table alone would be enough to prevent a branch factor that >>>>>terrible. >>>> >>>>How do you calculate branching factor here? >>> >>>A branching factor of 3 means that each node has in the average 3 child nodes >>>(This is the description i have found on an internet page). So the formula must >>>be: >>> >>>bf = ( Nodes [ply n] - nodes [ply n-1] ) / nodes [ply n-1] >>> >>>Excample: >>>Whole nodes until ply 5 = 4000 and whole nodes until ply 6 = 20000. >>>Then you got a branching factor of >>>bf [ply 6] = ( 20000 - 4000 ) / 4000 = 4.0 >>> >>>have a nice day >>>Andreas >> >>I know this :-) >> >>But there is the odd/even issue, so the b-factor can change drastically while >>moving from an odd ply to an even ply, and vice versa. > >I think the best is to calculate an average branching factor from all plys. > >bf[avg] = ( bf[2] + bf[3] + bf[4] ... + bf[n] ) / (n - 1) > >Andreas Yes, that seems to be the fair choice. Although I think the deeper plies tend to get more improtant. But then, what should be the last ply, odd or even? (e.g. search to 10 plies or 11?)
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