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Subject: Re: Q: Fail High percentage

Author: Landon Rabern

Date: 17:41:40 12/08/00

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On December 08, 2000 at 16:16:01, Robert Hyatt wrote:

>On December 08, 2000 at 13:21:21, Peter Fendrich wrote:
>
>>On December 08, 2000 at 13:06:43, Robert Hyatt wrote:
>>
>>>On December 08, 2000 at 12:56:09, Peter Fendrich wrote:
>>>
>>>>I looking for a measurement for move generation performance.
>>>>
>>>>Do you think FH/CountNodes, where FH is number of times the first generated move
>>>>was a Fail High, is a good measurement?
>>>>Do you have some other?
>>>>What's your figures?
>>>>I get some 50% and I have a feeling it's to low.
>>>>
>>>>//Peter
>>>
>>>
>>>The critical statistic I measure in crafty is this:  "For any position where
>>>I 'fail high' (return a score >= beta) what percentage of the time does it
>>>happen on the _first_ move?"  I generally average 92%.  Anything over 90% is
>>>reasonable.  Anything less means move ordering needs work.
>>
>>OK, it seems logical. I have in princple 3 types of FH:
>>  1) Hash table (without moving)
>>  2) Null Move
>>  3) Ordinary moves (including the hash table move)
>>
>>Do you include all these cases?
>>With only the third case counted I'm well over 90%
>>
>>//Peter
>
>
>Only 1 and 3.  2 is done at a different place in the search and doesn't
>really count in "move ordering".
>
>Actually, the way you wrote it, only 3 counts.  for 1) you are not searching
>a move, so that can't be counted.  2) doesn't count either...

I am getting about 80% on this, is this real bad?  I am not doing internal
interative deepening, do you think this will help a lot, or do you think there
is something else wrong.

I try moves in this order:

hash/pv
all captures sorted MVV/LVA
two killers
3 history scan moves
the rest


Regards,

Landon W. Rabern







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