(;
AB[cd][pd][pl][ml][oo][no][mo][pq][oq][nq][hq][pf][cc][cf][mn][pc][ic][ie][lc][ld][id][ig][ii][nc]
AW[dp][fq][kp][mp][on][nn][po][pp][qq][rp][ip][hp][di][eg][ee][dc][ob][jc][kc][je][ke][le][kh][kj]
C[Black's response to White's marked move?

Source:
    American Go Journal, Sept. 1981, Vol. 16, No. 4
    2nd Tengen Final, 1981, game 2
    Kobayashi Koichi 7P   vs.  Sugiuchi Masao 9P
    Kobayashi's commentary.]
TR[kj]
(;
B[fi]
C[Correct.
Black should take this vital point.
Black missed this line during the
game.];
W[ei];
B[fh];
W[dg];
B[fk]
C[Black has made a home in the
center.];
W[dl]
C[If White follows up with this
natural move...];
B[cq]
C[Now Black has a perfect excuse to
invade the corner.

But White's upper center group
is still thin, which Black can use
to advantage to make territory
on the right side.

See the inferior variation to see
what Black played in the game.]
)
    (;
    B[bo]
    C[Wrong.
Invading immediately throws the
game into confusion.];
    W[cp];
    B[cl];
    W[dk];
    B[dl];
    W[ek];
    B[bj];
    W[bi];
    B[cj];
    W[ci];
    B[bp];
    W[bq];
    B[cn]
    C[Black has to make life in gote.];
    W[db]
    C[White should have made this
sente move against the Black
corner.];
    B[cb];
    W[ik]
    C[And then begin an attack on
Black's center group.

Black can survive, but
White can build thickness,
which White can use to
invade Black's right side.]
    )
)
