[gnugo-devel] Bamboo connection : test case and patch

[Stéphane Nicolet]

In the attached test game GNU Go looses 8 stones at move 172 by
playing M16 instead of M15. Investigation (via the options -t -T)
shows that it considers the left part of the upper black group
to be dead despite the bambon joint. It seems to be an amalgamation
problem since the two parts of the bamboo are not in the same dragon.

So here is a patch with :

- a new test case in connection.tst (same position in the north but
  this time the left part of the bamboo is made with ~75 stones).
- a new connection pattern for conn.db which solves the problem

Stephane





**************************************

--- gnugo-3.5.4-cvs/patterns/conn.db      Sat Jan 24 04:40:42 2004
+++ gnugo-3.5.4/patterns/conn.db   Fri Jan 30 23:58:01 2004
@@ -707,4 +707,20 @@
 ;attack(a) && attack(b) && !xcut(c) && !xcut(d)


+Pattern CC520
+# Bamboo connection even if stones are not tactically safe.
+
+OO
+..
+OO
+
+:+,sC
+
+ab
+cd
+ef
+
+;(attack(a) || attack(e)) && !xcut(c) && !xcut(d)
+
+


--- gnugo-3.5.4-cvs/regression/connection.tst     Sat Jan 24 05:00:08  
2004
+++ gnugo-3.5.4/regression/connection.tst  Sat Jan 31 01:28:16 2004
@@ -382,6 +382,11 @@
 110 connect E3 G3
 #? [0]*

+# Checking bamboo connection : M16 is the only move to save the snake
+loadsgf games/connection5.sgf
+111 reg_genmove black
+#? [M16]
+
 # Report number of nodes visited by the tactical reading
 10000 get_reading_node_counter
 #? [0]&


--- /dev/null      Thu Jan  1 01:00:00 1970
+++ gnugo-3.5.4/regression/games/connection5.sgf   Fri Jan 30 23:56:39  
2004
@@ -0,0 +1,10 @@
+(
+;
+FF[1]
+GM[1]
+SZ[19]
+AP[Jago:Version 4.53]
+AB[ga][fb][fc][gc][hc][ic][kc][kd][lb][mb][me][nd][oe][ng][og][pg][pf][ 
pd][qd][qc][rc][ks][kr][kq][kp][ko][kn][km][kl][kk][kj][ki][kh][kg][ec][ 
dc][dd][cd][bd][cq][eq][ep][eo][en][em][el][ek][ej][ei][eh][ad][ae][af][ 
ag][ah][ai][aj][ak][al][am][aq][ap][ao][an][bq][cp][co][cn][cm][ck][ci][ 
ch][dh][cl][cj][fq][gq][gp][go][gn][gm][gl][gk][gj][gi][gh][hh][ih][ii][ 
ij][ik][il][im][in][io][ip][iq][pq][pk][ab][id][po][pp][pr][ps][pn][pm][ 
qm][rm][sm]
+AW[fa][ea][eb][cc][cb][gd][hd][ge][fe][hf][if][je][ke][gb][hb][ib][jb][ 
kb][lc][jg][jh][ji][jj][jk][jl][jm][jn][jo][jp][jq][jr][js][bc][ac][br][ 
cr][dr][er][fr][hr][db][hg][gg][fg][eg][ce][de][ed][be][bf][bg][bh][bi][ 
bj][bk][bp][bo][bn][bm][bl][dq][dp][do][dn][dm][dl][dk][dj][di][ar][cg][ 
dg][gr][ir][hq][hp][ho][hn][hm][hl][hk][hj][hi][fh][fi][fj][fk][fm][fl][ 
fn][fo][fp][fd][ie][sp][qs][qr][qq][qp][sq][sr][ss][rs][so][qo][qn][rn][ 
sn][rr]
+GN[connection5]
+)

test_game__010.sgf
Description: Binary data

connection5.sgf
Description: Binary data