EVENT
BOARDSIZE 19
SETUP W R10 D16 C4 
SETUP B P17 R16 Q4 
MARK \t@R10
COM
Problem 2. Black to play.  

This time the marked white stone is under the star point. In
which direction should Black attack ? 
ENDCOM
B 1 R12
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.  

The checking extension of Black 1 is the correct direction. The
distance from the small knight enclosure is perfect and Black
1 and ...  
ENDCOM
  VAR
  B 1 R8
  COM
  Failure.  

  Black 1 is the wrong direction.  
  ENDCOM
  W 2 R13
  COM
  White extends to 2 and, since this stone is two spaces from Black's
  corner enclosure, White's stones are not under much pressure.
  Moreover, Black's position below is thin.
  <=
  ENDCOM
  ENDVAR
W 2 R7
B 3 R5
MARK A@N3
COM
... 3 put severe pressure on White's stones. Later Black will
aim to enclose the corner with A.
<=
ENDCOM