(;
GM[1]
SZ[19]
AW[dd][cf][dj][dp][cp][gq][qn][qk][ok]
AB[kq][qp][op][oi][qi][pd][nc][id][fc]
TR[ok]
C[Problem 65. Black to play.  

White has just jumped into the center with the marked stone. How should Black attack ? ]
(;B[on]
TE[2]
C[Correct Answer.  

Black should jump to 1. ]
;W[mk];B[mi];W[kk]
LB[mk:2]
C[This drives White into the center with 2 and 4, but ... ]
;B[ki]
LB[rm:C][pk:B][pl:A][mi:3]
C[... Black can follow with 3 and 5 to map out a huge moyo in the upper right sector of the board. Later, Black can take some territory on the right side with the sequence Black A, White B, Black C. <= ]
)
(;B[mj]
C[Failure.  

Attacking with the knight's move of 1 is in the wrong direction. ]
;W[on]
C[White secures her stones with 2 and Black no longer has a vulnerable target. In the Correct Answer, Black naturally builds a moyo, while keeping White under pressure. White 2 also weakens the black stones below. <= ]
)
)