(;
GM[1]
SZ[19]
AW[ch][cd][ec][hc][qj][pb]
AB[cj][jc][pc][qe][oc]
LB[oc:2][pb:1]
C[Problem 66. White to play.  

White has attacked the small-knight enclosure by attaching at 1. How should White follow up his invasion after Black extends to 2 ? ]
(;W[qc]
TE[2]
C[Correct Answer.  

White easily lives in the corner ... ]
;B[qd];W[rc]
C[... with 3 ... ]
;B[ob];W[qa]
C[... and 5. However, the corner territory is small and White ends in gote, so the timing in playing these moves is crucial. <= ]
)
(;W[ob]
TE[2]
C[Correct Answer.  

Living in the corner is small, so White might play 1 ... ]
;B[qb];W[nc]
C[... and 3. ]
;B[lc]
C[If Black attacks with 4, ... ]
;W[ne]
LB[qc:C][qd:D][qf:B][pe:A]
C[... White jumps to 5, aiming to make sabaki by attaching at A. If then Black B, White plays C, if Black D, White answers with B. <= ]
)
)