Re: [gnugo-devel] more strategic defense moves

[Gunnar Farnebäck]

Arend wrote:
> Letting groups get weak and finally die is still one of GNU Go's main
> weaknesses. I have often seen that urgent moves did not even get
> a strategic defense bonus.
> 
> So this patch tries to address this by adding a "d" classification to 
> all fuseki type patterns where it seems obvious to me; it also adds a
> pattern to do a small knights extension from the 4th line when a longer
> extension is blocked.

I've had another thought on the weakness problem. Currently a dragon
can be declared very strong, i.e. weakness 0, either by having many
eyes, much surrounding moyo, or high escape value. It seems to me that
a dragon which only has a high escape value but is short on eyes and
moyo very often is indeed quite weak and risks being isolated and cut
off a few moves later.

What about something like this patch, or even more extreme
modifications? (Untested, no idea what it does to regressions.)

/Gunnar

Index: engine/dragon.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/dragon.c,v
retrieving revision 1.142
diff -u -r1.142 dragon.c
--- engine/dragon.c     1 Aug 2004 17:38:07 -0000       1.142
+++ engine/dragon.c     6 Aug 2004 22:15:01 -0000
@@ -2171,7 +2171,7 @@
 static struct interpolation_data moyo_value2weakness =
   { 5, 0.0, 15.0, {1.0, 0.65, 0.3, 0.15, 0.05, 0.0}};
 static struct interpolation_data escape_route2weakness =
-  { 5, 0.0, 25.0, {1.0, 0.6, 0.3, 0.1, 0.05, 0.0}};
+  { 5, 0.0, 25.0, {1.0, 0.6, 0.3, 0.25, 0.2, 0.15}};
 static struct interpolation_data genus2weakness =
   { 6, 0.0, 3.0, {1.0, 0.95, 0.8, 0.5, 0.2, 0.1, 0.0}};