(;AB[cr]AB[cq]AB[dq]AB[dp]AB[ep]AB[fp]AB[gp]AB[gq]AB[hq]AB[iq]AW[br]AW[bq]AW[cp]AW[co]AW[do]AW[eo]AW[fo]AW[go]AW[ho]AW[jp]AW[jq]AW[jr]AW[lr]AW[ip]AW[cs]AW[dr]AW[eq]AW[fq]C[black to live]AW[bp]AP[goproblems]
(;B[er];W[ds]
(;B[hs];W[fr];B[fs]
(;W[es]C[CHOICE]
(;B[gr]C[yes, ko - is the best black can do hereRIGHT])
(;B[gs];W[bs]))
(;W[gr]C[This variation is suggested by toqom. By playing this way, w takes away b's ko threat at b1.];B[hr];W[es];B[gs];W[bs];B[er];W[fr];B[fq]C[];W[eq]C[koRIGHT]))
(;B[fr];W[gs])
(;B[es];W[bs]
(;B[fr];W[gs])
(;B[gs];W[fr];B[fs];W[ir])
(;B[gr];W[hs])
(;B[ir];W[fr])
(;B[hs];W[fr]))
(;B[gs];W[fr]
(;B[gr];W[ir])
(;B[fs];W[ir])
(;B[ir];W[fs]))
(;B[ir];W[fr]
(;B[gr];W[fs])
(;B[fs];W[es]))
(;B[gr];W[ir])
(;B[hr];W[fr];B[fs];W[es])
(;B[fs];W[hs]))
(;B[es];W[ds]
(;B[fr];W[bs];B[er])
(;B[hs];W[fs])
(;B[gs];W[er])
(;B[gr];W[er])
(;B[ir];W[fs])
(;B[er]))
(;B[fr];W[ds]
(;B[ir];W[er])
(;B[hr];W[er])
(;B[es])
(;B[er]))
(;B[hs];W[er])
(;B[gs];W[er])
(;B[fs];W[ds]
(;B[fr];W[er])
(;B[hs];W[er])
(;B[ir];W[er])
(;B[er]))
(;B[gr];W[er])
(;B[ir];W[er])
(;B[is];W[er])
(;B[ds];W[es]
(;B[fr];W[hs]
(;B[fs];W[ds]
(;B[er];W[bs]
(;B[is];W[ir];B[hr];W[gs])
(;B[gs];W[hr])
(;B[ir];W[is])
(;B[hr];W[gs]))
(;B[hr];W[gs])
(;B[is];W[ir];B[hr];W[gs])
(;B[gs];W[hr]))
(;B[er];W[ds]
(;B[gs];W[hr])
(;B[is];W[ir])
(;B[hr];W[gs];B[fs];W[bs])
(;B[fs])))
(;B[fs];W[fr])
(;B[gr];W[bs])
(;B[ir];W[fr])
(;B[hs];W[fr])
(;B[hr];W[fr]))
(;B[hr];W[er]))
kaf