(;
AW[do][eo][fo][cp][gp][cq][dq][hq][dr][hr]
AB[bm][cm][bo][co][dp][ep][eq][er]
C[Save the isolated black stones.]
(;B[bq];W[bp]
(;B[br];W[es];B[fs];W[ds];B[fr];W[ap]
(;B[cr];W[bs]
(;B[cs];W[ar];B[as]C[RIGHT Black takes the ko first.
])
(;B[aq];W[cs];B[ar];W[as]
C[With such a big eye white wins the capturing race.
])
(;B[as];W[ar]C[White lives.
])
(;B[ar];W[cs]C[With such a big eye white wins the capturing race.
])
)
(;B[bs]C[
];W[gr]LB[bs:A]
C[Black A would have worked if the black stones on the right had had one extra liberty.
])
(;B[aq];W[bs]
(;B[cr];W[cs];B[ar];W[as]C[White's big eye wins the capturing race.
])
(;B[ar];W[cr])
(;B[as];W[ar]C[White takes the ko first. Black can do better.
])
)
(;B[ar];W[gr]C[White wins the race.
])
(;B[as];W[gr]C[White wins the capturing race.
])
(;B[cs];W[bs]
(;B[as];W[cr];B[ao];W[bs]
C[White takes the ko first. Black can do better.
])
(;B[cr];W[ar];B[as]C[RIGHT It's a ko and black takes first.
])
(;B[ar];W[cr]C[Seki.
])
(;B[aq];W[cr]C[White lives.
])
(;B[ao];W[cr]C[White lives.
])
)
(;B[ao];W[bs]
(;B[cr];W[ar]C[White lives.
])
(;B[ar];W[cr]C[Seki.
])
(;B[aq];W[cs]
(;B[as];W[ar]C[White takes the ko first. Black can do better.
])
(;B[ar];W[gr];B[cr];W[as]
C[White's eye is big, so white wins the capturing race by several moves.
])
)
)
)
(;B[ap];W[br]
(;B[ar];W[aq]C[White takes the ko first. Black can do better.
])
(;B[aq];W[ar];B[ao];W[cs])
)
)
(;B[ds];W[cs]
(;B[es];W[br]C[White lives.
])
(;B[bq];W[br]
(;B[bp];W[es];B[fs];W[ds];B[fr];W[ar])
(;B[es];W[bp])
)
)
(;B[bp];W[es]
(;B[fs];W[ds];B[fr];W[bq]
C[White wins the race because of his big eye.
])
(;B[cs];W[ds]C[White can connect.
])
)
(;B[ar];W[es];B[fs];W[ds];B[fr];W[gs]C[White is one liberty ahead.
])
(;B[br];W[es];B[fs];W[ds];B[fr];W[gr]C[White is one liberty ahead.
])
(;B[cs];W[es];B[fs];W[ds];B[fr];W[br];B[bp];W[bq];B[aq];W[ar];B[bs];
W[gr];B[ap];W[fq];B[cr];W[as];B[cs];W[fp])
(;B[es];W[br]
(;B[cs];W[ds];B[bp];W[bq];B[aq];W[ar];B[bs];W[ap];B[ao];W[fr]
(;B[cr];W[as];B[cs];W[fq];B[cr];W[fp])
(;B[aq];W[fq];B[cr];W[as];B[cs];W[fs])
)
(;B[ds];W[cs]C[White lives.
])
)
)
Hans