Re: [gnugo-devel] owl tuning question

[Arend Bayer]

On Sat, 7 Sep 2002, Evan Berggren Daniel wrote:

> I was looking at a problem found by matcher_check (test 14 in
> auto_nngs.tst), and I don't see why owl_attack and owl_does_attack fail to
> find the attack on E10 of F11.  dragon_status shows an illegal transition
> later on when F11 is played by black.

Probably that is a connection problem. I didn't check, but I think the
following happens (I hope I get coordinates right, I am writing this
from memory): GNU Go sees E10 is connected to G12. And it sees that G12
is connected to G14. Hence E10-G12-G14 is considered as a single dragon.
Which is obviously incorrect.
Also, as it is, owl doesn't care whether a tail gets lost, as long as the
dragon gets two eyes somewhere. So owl may just defend G12 and G14
after black plays F11, and hence F11 is not an owl attack.
After black plays F11, dragon amalgamation may be different.
I am actually not sure whether there is a good way to make a test out of
this.  "same_dragon E10 G14" might make sense.

> Also, is there a gtp command to give the reasons for a move?  should there
> be?
No there is none.
Hmm, I am not sure. The semantics of move reasons can change frequently,
most of them are specific to GNU Go and they probably require
human interpretation; and of course, they can be seen with -t.

Arend