[gnugo-devel] two new patterns, one new test

[Paul Pogonyshev]

this patch addresses the failure in ld_owl:168. it also adds another test, 
ld_owl:201, which is to check that gnu go now understands why Q19 is not good 
in this position.

the pattern in owl_defendpats.db makes gnu go believe that T19 works. maybe 
T19 is not the best solution (to me they all seem to be about equal 
"quality"), but since it does work, gnu go should better understand why. as 
T19 is tried first by owl code, it is now selected as an answer (good, 
problem solved).

D1424 (the new pattern) is much like D818b, but i'm not confident enough to 
start changing existing patterns. if anyone can merge D1424 into D818b, it 
will be good.

another pattern is in owl_vital_apats.db. it is needed to overcome the 
failure to see why "two certain eyes" can still be attacked. solves the new 
testcase.

i also had another look at VA50. it gives at least seki (as long as black has 
no other eyes), but as far as i understand, owl currently has no machinery to 
deal with sekis. it can also kill black if he can be forced to fill one of 
the two remaining liberties. however, we don't have machinery to determine 
this either. my eyespace/connection code would do here, if it worked properly 
;)

so i just wanted to ask, maybe it is better to comment out this pattern for 
now, or tweak its valuation?

Paul

p.s. i didn't run the regression suit, but the patch can hardly break         
     anything.


Index: patterns/owl_vital_apats.db
===================================================================
RCS file: /cvsroot/gnugo/gnugo/patterns/owl_vital_apats.db,v
retrieving revision 1.31
diff -u -p -r1.31 owl_vital_apats.db
--- patterns/owl_vital_apats.db 20 Oct 2002 10:43:25 -0000      1.31
+++ patterns/owl_vital_apats.db 14 Nov 2002 19:57:26 -0000
@@ -842,4 +842,17 @@ Pattern VA50
 :8,s,value(45)
 
 
+Pattern VA51
+# pp New pattern (3.3.12)
+
+|*Oo         start an unfavourable ko
+|.XO
+|X.X
+|.Xx
+|.O.
++---
+
+:8,-,value(35)
+
+
 # END OF FILE
Index: patterns/owl_defendpats.db
===================================================================
RCS file: /cvsroot/gnugo/gnugo/patterns/owl_defendpats.db,v
retrieving revision 1.72
diff -u -p -r1.72 owl_defendpats.db
--- patterns/owl_defendpats.db  11 Nov 2002 23:39:57 -0000      1.72
+++ patterns/owl_defendpats.db  14 Nov 2002 19:57:31 -0000
@@ -6599,4 +6599,15 @@ Pattern D1423
 :8,s,value(45)
 
 
+Pattern D1424
+# pp New pattern (3.3.12)
+
+|Oo?      avoid corner ko
+|.Oo
+|oX*
++---
+
+:8,-,value(45)
+
+
 # END OF FILE
Index: regression/ld_owl.tst
===================================================================
RCS file: /cvsroot/gnugo/gnugo/regression/ld_owl.tst,v
retrieving revision 1.18
diff -u -p -r1.18 ld_owl.tst
--- regression/ld_owl.tst       30 Oct 2002 00:10:16 -0000      1.18
+++ regression/ld_owl.tst       14 Nov 2002 19:57:32 -0000
@@ -314,6 +314,14 @@ loadsgf games/life_and_death/tripod9.sgf
 200 dragon_status C3
 #? [dead]
 
+# More life and death problems around tripod group.
+
+loadsgf games/life_and_death/tripod4.sgf
+# Black tries a bad defense. He must be punished.
+play black Q19
+201 owl_attack Q19
+#? [3 T15]
+
 # Mixed life and death problems.
 loadsgf games/life_and_death/mixed1.sgf
 300 owl_attack  C17