(;
AB[nr][mr][pq][dq][hp][qo][po][do]
AW[lr][mq][kq][np][oo][qn][pn][on][cm]
C[White plays.

Source:
    Tesuji Dictionary, Vol. 1, Tsuke #91,
    Segoe Kensaku & Go Seigen, Ishi Press]
(;
W[qq]
C[Moves like this one give defending players nightmares.]
(;
B[qr];W[rq];B[rr];W[pp]
C[And although Black can live, Black cannot avoid losing part of his group. ];
B[oq];W[ro]
)
    (;
    B[qp]
    C[If Black attacks from the other side...];
    W[rq];B[rn];W[pr];B[oq];W[rm]
    C[White lives in the corner, and Black is in serious trouble.]
    )
)
    (;
    W[pr]
    C[The right idea, but an inferior move order.];
    B[qq]
    C[Black can take the key point to force White to capture the 2 stones to the left.];
    W[or];B[oq];W[nq];B[qr];W[ns]
    C[And Black is somewhat better than in the main line. ]
    )
    (;
    W[ro]
    C[This slack move lets Black off the hook.];
    B[rp];W[rn];B[qq]
    C[And Black lives with a nice chunk of corner territory.]
    )
)

