(;
AB[qb][pc][pd][od][nd][qe][re]
AW[pb][ob][mc][lc][mf][pf][qf][rf][og][pi][qj][qk][nb][ld][le][mh]
C[White plays.]
(;
W[rb]
C[The obvious clamp tesuji.];
B[qa];W[rc]
C[And the obvious follow up.];
B[qc]
C[But now what does White do?]
(;
W[se];B[sd];W[rd]
C[White's moves have all been  forcing, but none of this appears to heading anywhere!];
B[sf];W[pe]
C[The vital point!]
(;
B[sg];W[sb];B[se];W[sc]
C[Black cannot make an eye on the right side, and White has made a bulky 5 in the corner.  Black dies.]
)
    (;
    B[se]
    C[This and the next move prevent White from creating a bulky 5 in the corner, but ...];
    W[sb];B[sc];W[qd]
    C[... White can change gears to win the semeai against Black's right side group.];
    B[sg];W[sh];B[rg];W[rh]
    C[Black cannot gain a 2nd liberty.]
    )
)
    (;
    W[rd]
    C[Fails];
    B[se]
    C[Black takes the key point.];
    W[pe];B[qd];W[sc]
    C[White's only chance to make a dead shape.  Otherwise, Black throws in here.];
    B[sb]
    C[But Black has time to throw in here to live.]
    )
)
    (;
    W[qa]
    C[Not good enough.];
    B[ra]
    (;
    W[rb];B[pa]
    (;
    W[qc];B[rc]
    C[White only has a ko.]
    )
        (;
        W[rc];B[qc];W[rd];B[sd];W[sb];B[se];W[sc];B[pe]
        C[Black is alive in seki.]
        )
    )
        (;
        W[qc];B[rb];W[rc];B[rd]
        (;
        W[sc];B[sd]
        C[Black lives.]
        )
            (;
            W[sb];B[pa]
            C[Black lives.]
            )
        )
    )
    (;
    B[rc]
    C[Black must defend here!]
    )
)

