(;
AB[db][dc][cc][cd][bd][ed][df][dg][dh]
AW[da][bb][bc][cb][eb][ec][fc][fd][ff][eg]
C[Black plays.

Source:
    The Endgame, Chap. 5, pp. 102-103
    Tomoko Ogawa & James Davies, Ishi Press]
(;
B[ac]
C[Black wants to prevent White from making a sente hane down the left side.  But this hane is not a good way to solve that problem.];
W[ab]
C[White can simply block.  Black is back to the original problem, but White has eliminated the bad aji in the corner.]
)
    (;
    B[ad]
    PL[B]
    C[This descent is better than the previous variation, because now Black has a follow-up move.];
    B[ab]
    C[Black can jump to here.  Unfortunately, White can even ignore this move.  So Black initial descent lacks punch.];
    W[ac]
    C[Notice though that White cannot block here.];
    B[ba]
    C[Taking the other 2-1 point, Black forces a ko for the corner.]
    )
    (;
    B[ab]
    C[The correct tesuji.  Now Black has a forcing follow-up.]
    PL[B]
    (;
    W[ac]
    C[White does not want to block here, because ...];
    B[ad]
    C[... Black can now descend in sente, threatening a ko from a previous variation.]
    )
        (;
        B[ac]
        C[Black's forcing move here is the follow-up that threatens to take the corner.]
        )
    )
)

