(;
AB[fc][cd][ed][gd][pd][qh][jq]
AW[ec][qc][qf][cj][do][pp][dq]
C[Black's response to the marked invasion?

Source:
    2004 American Go Yearbook, p. 45
    Hiuren Yang 1P game commentary
    2004 North American Fujitsu Qualifier
    White:  Huiren Yang 1P
    Black:  Thomas Hsiang 8d]
TR[qc]
(;
B[pc]
C[To block on the wider side is the standard joseki, but the top is too wide.];
W[qd];B[pe];W[rf];B[og];W[hc]
C[White can invade easily here.]
(;
B[gb]
C[If Black plays on the left, ...];
W[kd]
C[... White makes a position to the right.]
)
    (;
    B[jc]
    C[If Black plays on the right, ...];
    W[dc]
    C[... White extends to make life.]
    )
)
    (;
    B[qd]
    C[Blocking on this side is correct, and follows the actual game.];
    W[pc];B[od];W[rd];B[re];W[rc];B[qe];W[nc];B[qn]
    C[Black has sente to approach the lower right.];
    W[nq];B[gq]
    )
)

