Author: José Carlos
Date: 09:43:04 10/30/03
Go up one level in this thread
On October 30, 2003 at 12:27:16, Tord Romstad wrote:
>On October 30, 2003 at 11:05:41, Uri Blass wrote:
>
>>On October 30, 2003 at 10:46:09, Vladimir Medvedev wrote:
>>
>>>>>In order to find out how good my move ordering is, I determined to check
>>>>>which percentage of the cutoffs occured on the first move searched.
>>>
>>>Is branching factor more or less accurate parameter to evaluate quality of
>>>sorting moves?
>
>Perhaps, but how do you measure the branching factor? I have asked this
>question here before, but never recieved any answer.
After every iteration I print in my log file something like:
Branching factor:
- This iteration = Total Nodes / Nodes Last Iteration
- Acumulated: pow(Total Nodes,1.0 / Depth)
With this measure, I'm finding that my program has huges BF's (per iterartion)
in the first nodes, that go down to <= 3 after 5 iterations or so. But the
acumulated has a slow reducing behaviour, going to <= 3 after at least 12 plies.
I'm still working on understanding it :)
José C.
>>You can improve your branching factor by pruning or reduce it by extensions.
>
>Everybody always seem to claim that extensions increase the branching factor
>(I suppose that is what you meant, although you wrote "reduce"), but it is
>not at all obvious to me why this should be so. On the few occasions I have
>experimented with this myself, removing all extensions has not resulted in
>a noticably better branching factor. Of course the program needs fewer
>nodes to complete a given search depth without extensions, but the difference
>does not seem to be exponential. Perhaps more detailed and careful
>experiments would have given a different result.
>
>Tord
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.