EVENT
BOARDSIZE 19
SETUP W D16 D10 D6 D4 K16 O17 L17 
SETUP B G4 K4 Q4 Q6 Q10 Q16 Q14 M15 
MARK 1@Q6
COM
Problem 54. White to play.  

Black has strengthened his moyo on the right side with 1, but
this is not a good move, as it is premature. Where should White
play to punish Black for his mistake ? 
ENDCOM
W 1 K13
MARK A@K14
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

White 1 (or A) is the focal point of the two opposing moyos.
This move expands White's moyo while reducing the scale of Black's.
ENDCOM
  VAR
  W 1 K14
  USER
  CORRECT ANSWER
  ENDUSER
  COM
  Correct Answer.

  Also correct.
  <=
  ENDCOM
  ENDVAR
  VAR
  W 1 D14
  COM
  Failure.

  White misses her chance to seize the initiative when she meekly
  defends with 1.
  ENDCOM
  B 2 K15
  COM
  Black extend the scale of his moyo with 2 ...
  ENDCOM
  W 3 J15
  B 4 K14
  COM
  ... and 4. White has fallen behind.
  <=
  ENDCOM
  ENDVAR
B 2 K15
MARK A@K14 1@K13
COM
The two-space jump of White 1 is thinner than the tight one-space
jump at A in the Correct Answer, but it is a lot more severe.
Don't worry about Black trying to break through with the sequence
from 2 ...
ENDCOM
W 3 J15
B 4 K14
W 5 J14
B 6 J13
COM
... to 6.
ENDCOM
W 7 K12
MARK 5@J13 A@M14
COM
After White 7, White can aim at A or capture the black stone
at 5 in a ladder.
<=
ENDCOM