Re: [gnugo-devel] tuning patch

[Arend Bayer]

On Thu, 23 May 2002, Gunnar Farneback wrote:

> This patch does some mixed tuning.

Nice tuning! Two comments and one question follow below:

> Index: patterns/barriers.db
> ===================================================================

> +
> +
> +Pattern Intrusion52
> +# gf New pattern. (3.3.3)
> +
> +X.x
> +Q!.
> +.X.
> +
> +:8,B,value(30)
> +

I think one should add a line

>return (!xplay_attack(b,a))

(with b at ! and a at Q) to the pattern. Otherwise 'a' might get played
because of a followup value, although the lost liberty will mean we have
to come back and defend after the 'a'-'b' exchange. Also, maybe it is
more convenient to have "Intrusion6" generalized as below?


 ?QX
 X!!
-x..
+x.x

 :8,B,value(30)

 ?aX
 Xb!
 x..

 >return (!xplay_attack(b,a));



> +
> +Pattern Intrusion53
> +# gf New pattern. (3.3.3)
> +
> +X!.
> +QX!
> +
> +:8,B,value(50)
> +
> +Xa.
> +QB!
> +
> +;!oplay_defend(a,B)

I wondered whether it might be useful to generally add intrusion sources
around 'dead' opponent stones (where 'dead' means either dead or
critical and of the color not allowed to make the next move).

At the moment positions with a dead string in a chain of stones
surrounding territory are valued poorly by the influence code.

> Index: patterns/patterns.db

> +
> +Pattern Shape83
> +# gf New pattern. (3.3.3) (see trevorc:310)
> +
> +*X?        don't leave double atari behind
> +.OX
> +..O
> +
> +:8,sX,shape(-2)

I have worried about that shape, too! In another test case (where * was
on the 2nd line and could get captured directly after the X at 'd', O at
'c' exchange) I didn't understand why it didn't get rejecected by the
atari_atari blunder test, even if I set allowed_blunder_size to 1
(sorry, can't find the test case at the moment).
Can you explain what atari_atari_confirm_safety actually checks (or
should check)?

> +
> +*X?
> +daX
> +.cb
> +
> +;!oplay_defend_both(*,c,a,b) && oplay_attack(d,c,c)


Arend