EVENT
BOARDSIZE 19
SETUP W K17 L17 M18 M16 N16 O17 
SETUP B D16 H17 L18 M17 N17 N18 Q16 Q14 R10 
MARK 6@N16 5@N17 4@M16 3@N18 2@L17 1@L18
COM
Problem 19. Black to play.  

This time Black hanes from the other side and the moves continue
to 6. What should Black do now ? 
ENDCOM
B 1 O16
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Black 1 is a good move, ...
ENDCOM
W 2 O18
B 3 M19
W 4 Q17
  VAR
  W 4 O19
  COM
  Variation.

  If White wants to attack on the left, she will play 4 here.
  ENDCOM
  B 5 N19
  W 6 K18
  B 7 P17
  W 8 O15
  B 9 P16
  MARK B@K19 A@J19
  COM
  The moves continue up to 9, and Black gets a large profit in
  the corner. However, a white move at A or B, threatening Black's
  stones on the left and right, could later become troublesome.
  <=
  ENDCOM
  ENDVAR
B 5 P16
W 6 R17
COM
... even when White can live in the corner with the moves to
6.
ENDCOM
B 7 K18
COM
After Black 7, ...
ENDCOM
W 8 K15
MARK A@S16
COM
... White must fix up her shape by playing at 8, while Black
A is sente. Black is satisfied with this result.
<=
ENDCOM