Re: [gnugo-devel] thrashing dragons again

[Gunnar Farnebäck]

Arend wrote:
> - We use the thrashing dragon heuristic much more often: Do it even if we
> are behind (up to 30 pts), and don't bother to make it dependant on the

The code comments are out of sync with this change.

> move value without the thrashing dragon heuristic. This means we don't
> have to run review_move_reasons() twice in the case of a thrashing
> dragon. The rational is that we still won't miss an urgent move somewhere
> else, as the thrashing dragon moves would have to have higher value
> that this urgent moves.

I'm not sure I agree with this. Consider the case where the game is
pretty much over and GNU Go is about to lose by half a point. Then the
opponent (stupid computer or confused human) inexplicably adds a stone
to a dead dragon without a working followup. I would be very annoyed
if GNU Go answered with a restraining move inside own territory, not
taking the gift.

> strategy3:141   PASS C7 [C7]
> Good. (Papering over owl bug.)

Some of these might be good to add as owl test cases now that they
have become hidden.

> nngs3:580       FAIL A4 [H3|J5|K3|J3]
> Very bad. A4 should not get a strategic attack move reason vs C6.

Any suggestion how to characterize the A4 move so that it can be
avoided? We already have a reduction in the attack thrashing dragons
bonus for connections to inessential stones, but sometimes those moves
are good ideas.

A different solution for this testcase would be to add a c (weak
connection) pattern for H3. Strictly speaking it does connect but the
cutting stones get too many liberties for the connection reading to
realize this.

/Gunnar