(;GM[1]FF[4]SZ[19]
GN[Critical point?]
PC[http://senseis.xmp.net/?RTGProblem20/Attempts]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?RTGProblem20/Attempts

Critical point?]
PL[B]

AB[oa][qa][ob][pb][nc][pc][od][pd][qd][rd]
AW[ra][mb][nb][mc][qc][rc][md][sd][ne][oe][pe][qe][re][se]

;B[qb]C[B1]MN[1]
;W[nd]C[W2]MN[2]
;B[sb]C[B3]MN[3]

;
)
