(;
AB[ca][fb][fc][ec][cd][dd][cf]
AW[ea][eb][bc][cc][dc]
C[Black plays.]
(;
B[ba]
C[An odd-looking move, but the vital point for both sides.];
W[db]
C[Otherwise, Black plays here to capture the 2 top stones.];
B[bd]
C[White has a dead shape.]
)
    (;
    B[db]
    C[Bad timing.];
    W[ba]
    C[White takes the vital point.]
    (;
    B[fa]
    C[Black can capture 2 stones, but ...];
    W[cb];B[da];W[ab]
    C[... White can make eyes.]
    )
        (;
        B[bb]
        C[Doesn't work either.];
        W[cb];B[aa];W[da]
        C[White has a ko.]
        )
    )
    (;
    B[bd]
    C[Too slow.];
    W[ba]
    C[Again, White takes the vital point.];
    B[bb];W[ab]
    C[For example, White has a ko.]
    )
    (;
    B[bb]
    C[Also fails.];
    W[ba]
    C[For example ...]
    (;
    B[cb];W[ab]
    C[Leads to a ko.]
    )
        (;
        B[aa];W[cb];B[fa];W[ac];B[db];W[ab];B[da];W[ba]
        )
    )
)

