(;
AB[dd][fd][pd][pf]
AW[nc][hc][cf][fb]
TR[fb]
C[Black's response to the marked play?

Source:
    "Practical Tactics and Tesuji", Rin Kaiho 9p
    Go World #11, p. 44]
(;
B[ce]
C[Simplest and safest.];
W[df]
C[White makes a solid shape, but ...]
(;
B[dc]
C[... Black makes good shape, especially if this situation arises in a handicap game.]
)
    (;
    B[eb]
    C[Another good looking move, but an overplay.];
    W[ec];B[db];W[fc]
    C[White threatens to either seal Black into the corner, or invade the corner.];
    B[de]
    C[A desparate attempt to defend against both of White's threats.];
    W[bc]
    C[A tesuji.];
    B[cd]
    C[Another desparate move.];
    W[bf];B[bd]
    C[The result is bad for Black.  White is too strong on the outside.

Also bad for Black is that White can later play the following sequence.];
    W[cb];B[dc];W[ad];B[ae];W[ab]
    C[White has an unfavorable 2 step ko, but if White does win the ko, Black has no eye space.]
    )
)
    (;
    B[cc]
    C[Also correct.  Black aims at a pincer on either the top or left side: however, the disadvantage is that Black has a less settled shape than the main line.]
    )
    (;
    B[ec]
    C[A mistake.];
    W[cc]
    C[White takes advantage of the weak corner to invade.];
    B[cd];W[bd];B[be];W[bc];B[ce];W[eb]
    C[Not only does Black lose territory, but also Black's group may be subject to attack later.]
    )
    (;
    B[db]
    C[This shape is often correct, but not here!];
    W[cc]
    C[White's peep here exposes Black's weakness.];
    B[cd];W[bd];B[be];W[bc];B[ce];W[dc];B[ec];W[eb];B[df]
    C[Black defends on the left, but the result is similar to the previous variation.  Black's group may still be subject to attack later.]
    )
)

