(;
AB[cr][cq][ds][cp][co][dq][do][eo][ep][fp][gq][hq][iq][kq]
AW[bs][br][bq][bp][bo][cn][dn][en][fo][go][gp][fq][eq][es][gr]
C[Black plays.]
(;
B[er]
C[Obvious, but fails.];
W[fr];B[fs];W[gs];B[hr]
C[Black only has a ko.]
)
    (;
    B[fr]
    C[Also looks good, but fails.];
    W[er];B[gs]
    C[Stylish, but ...];
    W[cs]
    C[... Black's inside group doesn't have enough liberties.]
    )
    (;
    B[dr]
    C[The only move.];
    W[fr]
    (;
    B[hr]
    C[But this move is a mistake.];
    W[gs]
    (;
    B[hs];W[cs]
    C[Black only has a seki.]
    )
        (;
        B[er]
        C[Worse.];
        W[cs]
        C[Ko.]
        )
    )
        (;
        B[gs]
        C[Again the only move!];
        W[hr];B[ir];W[hs];B[er];W[cs]
        C[Black looks dead?];
        B[fs];W[es];B[fs]
        C["One eye vs. no eye".  Black wins the semeai.]
        )
    )
)

