(;
AB[ba][bb][ib][cc][cd][ce][hc][hd][dd][de][fd][fe][jd][pd][ee][ge][bg][cg][cm][dp]
AW[da][ga][cb][fb][fc][hb][bc][dc][ec][gc][gd][ed][he][hf][df][fg][bh][ch][dh][po]
PL[W]
C[Play the next couple moves to reach the problem position.

Source:
Go World #25, pp. 17-19
White:  Miyamoto Naoki 9P
Black:  Takemiya Masaki 9P
Commentary:  Miyamoto 9P];
W[dg]
C[In the game White connected here, seemingly to fix the defect in White's shape.];
B[pj]
C[So Black takes this large right side point, incorrectly thinking that White's previous move was purely defensive.

Problem:  What is White aiming for in the top left?]
(;
W[ab]
C[This hane is usual in type of shape, but is not White's plan, as the following sequence shows. ];
B[bd];W[ac];B[ad];W[bf]
C[White's placement seems to put Black's entire group in trouble, because Black has only one eye.  But ...];
B[cf];W[ag];B[af]
C[... Black's throw-in ruins White's hopes in this sequence.];
W[ae];B[be]
C[Black lives.]
)
    (;
    W[ad]
    C[But this unusual tesuji works very well. ]
    (;
    B[ae]
    C[Attaching here doesn't work.];
    W[be]
    C[This hane kills Black unconditionally.]
    )
        (;
        B[ab]
        C[Blocking here is just as bad.];
        W[ag];B[af];W[bf]
        C[Again, Black is unconditionally dead.]
        )
        (;
        B[bd]
        C[So, Black must atari here.];
        W[ae];B[ag]
        C[Black must prevent White from linking up, but ...];
        W[ab]
        TR[pj]
        C[White makes a huge ko.

Black cannot afford to lose this ko, so in the actual game, White is able to play 2 moves elsewhere on the board.  Black's marked play was an overplay.]
        )
    )
)

