Re: [gnugo-devel] Gnu Go 3.2 possibly correctable flaw in play

[bump]

SP Lee wrote:

> I think it's certainly not easy to fix this problem, because there are
> hardly clear cut moves which could be said as the only correct solution
> at various stages of the game. One thing is sure, gnugo doesn't know
> when and how to suppress a moyo. The cosmic patch seems to concentrate
> on building moyo, but not suppressing a moyo. Actually at move 12, the
> black moyo is already too huge and has to be suppressed at the position
> like K3. The moves gnugo played may be less efficient, but not
> worthless. Gnugo has to know that the moves like K3 is larger than
> anything else.

Right, move 12 is crucial in this game. Unfortunately 3.3.23 also plays 
W:12 at P16.

You can argue that move 10 is unnecessary but after move 10, W has
played 3 moves in the upper right and B has played one, so it's like
W has invested two moves to make a shimari.

P16 is overvalued at 21 points:

  P16:   11.00 (followup) - threatens to capture P17
  P16: 11.95 - change in territory
  P16:   17.45 - total followup value, added 6.45 as territorial followup
  P16: 8.73 - added due to followup (17.45) and reverse followup values (0.00)
  P16: 0.52 - connects strings (connect value 5, shape factor 0.104)
Move generation values P16 to 21.19

K3 is not considered, nor are other moves in this area! 

The patch below fixes that. It has to be written as several patterns 
due to the fact that every pattern has to have an anchor.

After this patch W plays K3 in this game. The problem remains,
that P16 is overvalued, so W will go back and play it fairly
soon in this game.

Dan


Index: patterns/fuseki.db
===================================================================
RCS file: /cvsroot/gnugo/gnugo/patterns/fuseki.db,v
retrieving revision 1.30
diff -u -r1.30 fuseki.db
--- patterns/fuseki.db  18 Jul 2003 18:59:22 -0000      1.30
+++ patterns/fuseki.db  26 Jul 2003 14:16:44 -0000
@@ -1722,6 +1722,124 @@
 ;x_alive_somewhere(a,b,c,d,e,f) && x_alive_somewhere(g,h)
 
 
+Pattern F812
+
+|..xxx.........xxx..|             wariuchi
+|..xxx.........xxx..|
+|..xxx.........xxx..|
+|..Xxx....*....xxx..|
+|...................|
+|...................|
++-------------------+
+
+:8,Fj
+
+|..xxx.........xxx..|
+|..xxx.........abc..|
+|..xxx.........def..|
+|..Xxx....*....ghi..|
+|...................|
+|...................|
++-------------------+
+
+; x_somewhere(a,b,c,d,e,f,g,h,i)
+
+
+Pattern F813
+
+|..xxx.........xxx..|             wariuchi
+|..xxx.........xxx..|
+|..xxx.........xxx..|
+|..xXx....*....xxx..|
+|...................|
+|...................|
++-------------------+
+
+:8,Fj
+
+|..xxx.........xxx..|
+|..xxx.........abc..|
+|..xxx.........def..|
+|..xXx....*....ghi..|
+|...................|
+|...................|
++-------------------+
+
+; x_somewhere(a,b,c,d,e,f,g,h,i)
+
+
+Pattern F814
+
+|..xxx.........xxx..|             wariuchi
+|..xxx.........xxx..|
+|..xxx.........xxx..|
+|..xxX....*....xxx..|
+|...................|
+|...................|
++-------------------+
+
+:8,Fj
+
+|..xxx.........xxx..|
+|..xxx.........abc..|
+|..xxx.........def..|
+|..xxX....*....ghi..|
+|...................|
+|...................|
++-------------------+
+
+; x_somewhere(a,b,c,d,e,f,g,h,i)
+
+
+
+Pattern F815
+
+|..xxx.........xxx..|             wariuchi
+|..xxx.........xxx..|
+|..xXx.........xxx..|
+|..xxx....*....xxx..|
+|...................|
+|...................|
++-------------------+
+
+:8,Fj
+
+|..xxx.........xxx..|
+|..xxx.........abc..|
+|..xXx.........def..|
+|..xxx....*....ghi..|
+|...................|
+|...................|
++-------------------+
+
+; x_somewhere(a,b,c,d,e,f,g,h,i)
+
+
+
+Pattern F816
+
+|..xxx.........xxx..|             wariuchi
+|..xxx.........xxx..|
+|..xxX.........xxx..|
+|..xxx....*....xxx..|
+|...................|
+|...................|
++-------------------+
+
+:8,Fj
+
+|..xxx.........xxx..|
+|..xxx.........abc..|
+|..xxX.........def..|
+|..xxx....*....ghi..|
+|...................|
+|...................|
++-------------------+
+
+; x_somewhere(a,b,c,d,e,f,g,h,i)
+
+
+
 ################
 # Miscellaneous
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