EVENT
BOARDSIZE 19
SETUP W C17 C16 D15 F16 G16 J15 C11 Q3 R5 Q8 R11 J4 H4 J6 G7 
SETUP B C18 D17 E18 F17 H17 D3 C6 J3 K3 K4 K5 N3 R13 R16 P17 
COM
Problem 164. Black to play.  

The game is on the border of the fuseki and the middle game.
Now is Blacks chance to seize the initiative. If he plays the
right move, victory will be within his grasp.  
ENDCOM
B 1 D10
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

The shoulder hit of Black 1 is the perfect point. It prevents
the four stones at the bottom from joining up with their allies
in the upper left to make a huge moyo in the center.
<=
ENDCOM
  VAR
  B 1 K16
  COM
  Failure.

  Locally, Black 1 at the top is a good move.
  ENDCOM
  W 2 K15
  COM
  However, White will push with 2 ...
  ENDCOM
  B 3 L16
  W 4 L15
  COM
  ... and 4, ...
  ENDCOM
  B 5 M16
  W 6 D8
  COM
  ... then play 6, making a deep moyo in the center.
  <=
  ENDCOM
  ENDVAR
  VAR
  B 1 C9
  COM
  Failure.

  Although in the right direction, Black 1 is too low.
  ENDCOM
  W 2 D9
  COM
  White will attach with 2.
  ENDCOM
  B 3 D8
  W 4 E9
  B 5 C10
  W 6 D11
  COM
  After White 6, White has again made a large-scale moyo in the
  center.
  <=
  ENDCOM
  ENDVAR