Re: [gnugo-devel] influence speed exactness tradeoff

[Gunnar Farneback]

Arend wrote:
> The breakage is 3 PASSes and 3 FAILs. trevorb:620 is the only bad fail.
> The problem with nicklas4:1201 is hardly related and it's mostly luck it
> passed before. G12 in trevorc:890 is absolutely playable.
> 
> I am not sure whether this is a good tradeoff. Opinions?

We have made similar tradeoffs before, e.g. setting the fourlib_depth
to 0 during make_domains(). In my experience these have often caused a
fair amount of trouble, especially when inaccurate results have
poisoned the caches.

This particular tradeoff is probably okay though.

> I will probably also try out two more exactness-speed tradeoffs, to make
> owl and influence reading calls less expensive:
>  * disable all (including legal) ko captures (as all the helper
>    functions do not even test for ko results, this seems a reasonable
>    thing to do).

I'm doubtful about this and also about the premise. Although there are
no explicit tests for KO_A and KO_B in the constraints, there's an
important distinction between "== WIN" and "!= 0".

>  * disable passes (which are used, though somewhat hidden, for the
>    defender) in the reading code -- this will be more convenient to try
>    after a little more reading.c clean-up.

Can you explain what you mean here? It's vital that the defender is
allowed to pass in certain seki positions or where the only local
moves are to fill in one of two one-space eyes.

/Gunnar