Re: [gnugo-devel] report on gnu go 3.5.2

[Gunnar Farneback]

Tom Bryce wrote:
> Not sure who to email this too, but I attach a .sgf save of a gnugo
> 3.5.2 game.

This is the right place.

> I am reporting a recurring mistake that should be added to the
> pattern database. Notice in the lower right hand corner of this
> game, gnugo attempts to invade at the 3,3 point, when I have a stone
> at the 4,4 point and extended to the 4,6 (6,4?) point and the 5,3
> (3,5?) point. This invasion fails with the extension you see, to 5,2
> (2,5?). This is a guaranteed death for this invasion.

No, it can live, it's just that GNU Go follows up incorrectly. White
must respond with the peep at P3.

> I am writing not because Gnugo made a mistake, but because this
> theme *constantly* comes up in my games with gnugo. For me, it is a
> surefire way to kill some of its stones and strengthen my position,
> but I think it could be added to the database of positions that it
> recognizes so it will not keep repeating this mistake.

Agreed, this is a common and important position. Appended is a test
suite patch adding 17 test cases to ld_owl.tst for some common
variations of this invasion.

/Gunnar

Index: regression/ld_owl.tst
===================================================================
RCS file: /cvsroot/gnugo/gnugo/regression/ld_owl.tst,v
retrieving revision 1.35
diff -u -r1.35 ld_owl.tst
--- regression/ld_owl.tst       24 Jan 2004 04:04:57 -0000      1.35
+++ regression/ld_owl.tst       27 Jan 2004 18:57:31 -0000
@@ -414,6 +414,50 @@
 414 owl_attack Q4
 #? [1 S2]
 
+# Problems arising from a 3-3 invasion.
+loadsgf games/life_and_death/invasion1.sgf
+501 owl_defend C17
+#? [1 C15]
+502 owl_defend R17
+#? [1 (R14|S14|R16)]
+503 owl_defend R3
+#? [1 S2]
+504 owl_attack C3
+#? [1 B1]
+
+loadsgf games/life_and_death/invasion2.sgf
+505 owl_attack C17
+#? [1 (C19|B19)]
+506 owl_defend R17
+#? [1 S16]
+507 owl_defend R3
+#? [1 S2]
+508 owl_defend R5
+#? [1 (S2|S7)]
+509 owl_defend C5
+#? [1 A5]
+
+loadsgf games/life_and_death/invasion3.sgf
+510 owl_defend C15
+#? [1 B15]
+511 owl_defend R15
+#? [1 (R12|R11)]
+512 owl_defend R3
+#? [1 S5]
+513 owl_defend C3
+#? [1 C2]
+
+loadsgf games/life_and_death/invasion4.sgf
+514 owl_defend C17
+#? [1 B16]
+515 owl_defend R15
+#? [1 S15]
+516 owl_defend R3
+#? [1 S2]
+517 owl_defend C3
+#? [1 C8]
+
+
 # Report number of nodes visited by the tactical reading
 10000 get_reading_node_counter
 #? [0]&
Index: regression/games/life_and_death/invasion1.sgf
===================================================================
RCS file: regression/games/life_and_death/invasion1.sgf
diff -N regression/games/life_and_death/invasion1.sgf
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ regression/games/life_and_death/invasion1.sgf       27 Jan 2004 18:57:31 
-0000
@@ -0,0 +1,10 @@
+(;GM[1]FF[3]
+RU[Japanese]SZ[19]HA[0]KM[5.5]
+PW[White]
+PB[Black]
+GN[invasion1]
+DT[2004-01-27]
+SY[Cgoban 1.9.10]TM[30:00+30:00/25];
+AW[cc][fc][nc][qc][fd][jd][nd][qe][bn][bo][co][qo][cp][fp][jp][np][qp][cq][fq][nq][qq]
+AB[eb][ob][ec][oc][dd][pd][pe][df][pf][cj][qj][bm][cn][dn][pn][qn][do][po][dp][pp][eq][oq][er][or]
+)
Index: regression/games/life_and_death/invasion2.sgf
===================================================================
RCS file: regression/games/life_and_death/invasion2.sgf
diff -N regression/games/life_and_death/invasion2.sgf
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ regression/games/life_and_death/invasion2.sgf       27 Jan 2004 18:57:31 
-0000
@@ -0,0 +1,10 @@
+(;GM[1]FF[3]
+RU[Japanese]SZ[19]HA[0]KM[5.5]
+PW[White]
+PB[Black]
+GN[invasion2]
+DT[2004-01-27]
+SY[Cgoban 1.9.10]TM[30:00+30:00/25];
+AW[cc][fc][nc][qc][ad][cd][fd][jd][nd][be][qe][qf][cn][qn][co][qo][bp][fp][jp][np][rp][cq][fq][nq][qq][br]
+AB[eb][ob][ec][oc][dd][pd][qd][ce][pe][bf][df][pf][cj][qj][bm][cm][qm][dn][pn][do][po][cp][dp][pp][qp][eq][oq][er][or]
+)
Index: regression/games/life_and_death/invasion3.sgf
===================================================================
RCS file: regression/games/life_and_death/invasion3.sgf
diff -N regression/games/life_and_death/invasion3.sgf
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ regression/games/life_and_death/invasion3.sgf       27 Jan 2004 18:57:31 
-0000
@@ -0,0 +1,10 @@
+(;GM[1]FF[3]
+RU[Japanese]SZ[19]HA[0]KM[5.5]
+PW[White]
+PB[Black]
+GN[invasion3]
+DT[2004-01-27]
+SY[Cgoban 1.9.10]TM[30:00+30:00/25];
+AW[cc][fc][nc][qc][bd][fd][jd][nd][rd][ce][qe][re][cf][qf][bg][rg][bn][rn][bo][co][qo][fp][jp][np][cq][fq][nq][qq]
+AB[eb][ob][qb][bc][ec][oc][rc][cd][dd][pd][qd][de][pe][df][pf][cg][qg][cj][qj][bm][cn][dn][pn][qn][do][po][dp][pp][eq][oq][er][or]
+)
Index: regression/games/life_and_death/invasion4.sgf
===================================================================
RCS file: regression/games/life_and_death/invasion4.sgf
diff -N regression/games/life_and_death/invasion4.sgf
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ regression/games/life_and_death/invasion4.sgf       27 Jan 2004 18:57:31 
-0000
@@ -0,0 +1,10 @@
+(;GM[1]FF[3]
+RU[Japanese]SZ[19]HA[0]KM[5.5]
+PW[White]
+PB[Black]
+GN[invasion4]
+DT[2004-01-27]
+SY[Cgoban 1.9.10]TM[30:00+30:00/25];
+AW[cc][fc][nc][qc][fd][jd][nd][rd][ce][qe][bf][rf][bn][rn][bo][co][qo][ro][bp][fp][jp][np][rp][bq][cq][fq][nq][qq][br]
+AB[eb][ob][ec][oc][cd][dd][pd][qd][de][pe][df][pf][qf][cj][qj][cn][dn][pn][qn][do][po][cp][dp][pp][qp][dq][eq][oq][cr][er][or][qr][bs]
+)