Re: [gnugo-devel] Escape

[Gunnar Farneback]

Dan wrote:
> Possibly we should add ESCAPE to the possible results
> which would be ordered 0, KO_B, KO_A, ESCAPE, WIN. Since
> cache.h budgets 4 bits for the result we could do this.

This ordering is fine for owl_defend, but when attacking ESCAPE should
come between 0 and KO_B.

> The owl code would not be run twice but at least we'd
> track whether escape was a factor in the result.

Running the code twice may not be as bad as it sounds. If the first
pass only considers moves with a definite eye-making purpose, it's
quite possible that it can become much faster than the owl code is
today, especially for big dragons with much surrounding moyo. In fact
these savings may very well offset the increased cost of running the
owl code twice for the non-locally alive dragons.

> Then one could give priority to defending a dragon whose
> life depends on escape.

This is certainly what we want to be able to do. Similarly we could
give a bonus for moves reducing the surrounding moyo or escape
potential of opponent dragons which need to escape.

/Gunnar