(;
AB[dd][pd][pp][pj][dj][dp][jj][dn][jp][np][po][no]
AW[fq][nq][oq][pn][mp][ko]
TR[ko]
C[Black's response to the marked play?

Source:
    "Masterpieces of Handicap Go"
    Kobayashi Koichi 9P vs. Sakai Naoki 2d
    American Go Journal, Vol. 30, No 4, pp. 21-22]
(;
B[kp]
C[Doubtful.];
W[mo]
C[After White simply pushes up, Black's groups to the right and to the left may come under attack.]
)
    (;
    B[jo]
    C[The game move, but not the best.];
    W[kn]
    C[White can now make forcing moves poking into the center, and then ...];
    B[jn];W[km];B[il];W[qr]
    C[... extend into the corner.  White's bottom group is safe and Black's lower right group is under pressure.]
    )
    (;
    B[pq]
    C[The 100% correct move.  Black takes the initiative by making the corner group safe, while keeping the pressure on White's bottom group.];
    W[kp]
    C[After White defends, ...];
    B[jq]
    C[... Black continues the attack, and then ...]
    (;
    W[kq];B[gp]
    C[... Black sets up an imposing position.]
    )
        (;
        W[fo]
        C[White does not have time to jump out here, because ...];
        B[lr]
        C[... Black destroys the eye-shape here.];
        W[mq];B[gp];W[fp];B[in]
        C[And Black splits White into 2 weak groups.  This result is not good for White.]
        )
    )
)

