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Subject: Re: How to order moves (& others)

Author: Robert Hyatt

Date: 08:07:16 03/30/00

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On March 30, 2000 at 06:04:42, Jan Pernicka wrote:

> Hi,
>I have several questions:
> 1) How do you order your moves to get as much cutoffs as possible
>     (more than methods - captures,PV,killers... I'm interested in their
>    "order of importence" - i.e. which one goes 1st,2nd ....)

Here is mine:

1.  hash table move.
2.  captures that don't appear to lose material using a SEE procdedure,
ordered from biggest gain to equal exchanges.
3.  2 killer moves.
4.  up to 4 history ordered moves (history heuristic)
5.  rest of the moves.

> 2) Is there any common measure of performance of chess program?
>    Well, nodes per second(NPS) say nothing about numbers of cutoffs
>    and on the other hand serching depth(SD) is dependent on the state
>    of game(in endgame it's usually much greater...),
>    so it seems reasonable to introduce measure NPS*SD (or some other
>    formula which gets together these values) which could be more
>    general and can better show performance rather than pure speed.
>    Note: By performance I DON'T mean its strength (no ELOs)
>
> Thank you in advice for comments and answers.
>
>       Jan Pernicka


In crafty I produce the statistic "fh:" in the search output.  This is a
percentage, and indicates that for any position where a fail high was
found, it was found on the first move searched this percentage of the time.
My usual number averages about 92%.  Which means 8% of the time a fail high
occurs on a move other than the one tried first.



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