Re: [gnugo-devel] The killer heuristic

[Arend Bayer]

Evan wrote:

> On Sat, 25 Jan 2003, Arend Bayer wrote:
> >
> > Below are numbers from CVS at the same time. It seems your patch saves
> > about 1.5% on average.
> > (There are also some deviations for owl nodes and connection nodes,
> > not sure where they come from.)
>
> I assume they come from cases where the new ordering results in a
> different move being returned by attack() or find_defense().  Sometimes
> the actual move is used, eg in the owl code the result of attack() on the
> origin of the dragon is tried as an owl attack.  This also occurs with
> other changes to tactical move ordering, eg my move ordering tuning patch
> from a while ago had a small regression delta.

I _think_ what you are saying is incorrect. Your patch only effects
results of do_attack when called from a defend? function. But the
externally visibly behaviour of attack() and find_defense() should not
change at all.

I think it is a platform dependency. The relatively large deviations
in connection nodes (0.5%) can be explained from floating point rounding
problems in readconnect.c. As for owl nodes I am not sure.

Arend