EVENT
BOARDSIZE 19
SETUP W D16 C14 D10 D4 C4 G3 R6 R9 P9 
SETUP B L3 R4 P4 P11 R11 Q16 O17 J16 F17 
MARK \t@P9
COM
Problem 65. Black to play.  

White has just jumped into the center with the marked stone.
How should Black attack ? 
ENDCOM
B 1 P6
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Black should jump to 1.
ENDCOM
  VAR
  B 1 N10
  COM
  Failure.

  Attacking with the knight's move of 1 is in the wrong direction.
  ENDCOM
  W 2 P6
  COM
  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.
  <=
  ENDCOM
  ENDVAR
W 2 N9
B 3 N11
W 4 L9
MARK 2@N9
COM
This drives White into the center with 2 and 4, but ...
ENDCOM
B 5 L11
MARK C@S7 B@Q9 A@Q8 3@N11
COM
... 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.
<=
ENDCOM