(;
AB[qd][pe][oq][mq][jo][iq][hp][fp][ep][cp][co][do][cn][cl][dj][cc][ce][ed][fd][fc][gd][eb]
AW[oc][qj][qp][po][np][cq][dq][dp][eq][gr][eo][en][dn][el][hm][db][ec][dc][fb][ga][gc][hc][hb]
C[Black plays:  A, B, or C?

Source:
    Go World #5, Jan-Feb 1978, p. 71
    Blueprint 361]
LB[fj:A][mc:B][jm:C]
(;
B[jm]
C[Correct.  Black presses White's weak center group.];
W[fj]
C[White can extend toward Black's frameworks, ...];
B[fi]
C[... but Black can effectively block here.];
W[gi];B[fh];W[ej];B[di]
TR[jm]
LB[pk:A]
C[White has only induced Black to solidify the left side territory.

In addition, Black's marked move also limits  the growth of White's right side potential.  For example, Black threatens A on the right side.]
)
    (;
    B[fj]
    C[Black can try to enlarge the left side directly.];
    W[jm]
    C[Now White runs out to the right.];
    B[mp]
    C[Black strengthens the lower side.];
    W[lm]
    LB[dd:A][de:B][gf:C]
    C[And White must defend the center again.

Black's left side framework is certainly bigger than the previous variation, but White can now reduce with A, Black B, White C.

In addition, White's right side framework is taking on size.]
    )
    (;
    B[mc]
    C[Trying to reduce White's top side territory is a not a good plan.];
    W[oe];B[of];W[ne];B[le];W[nf]
    LB[ie:A]
    C[But now White has split Black into 2 weak groups.  Black has to assume trouble with at least one of the 2 groups.  And if White can play A to attack the group to the right, White will then be able to reduce Black's left side.  Black would then find winning nearly impossible.]
    )
)

