EVENT
BOARDSIZE 19
SETUP W C16 D14 C4 E4 R4 R5 R8 
SETUP B E17 K17 Q16 L3 R3 S3 Q4 P4 
COM
Problem 100. White to play.  

There are a lot of good points that White wants to play. However,
one of these points takes precedence over all the others. Where
should White play ? 
ENDCOM
W 1 R11
MARK A@R10
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

The extension of White 1 is the most important point on the board
for White. With this move, all of her groups are strong. If Black
is allowed to make the checking extension to A, the game would
become difficult for White.
<=
ENDCOM
  VAR
  W 1 C10
  COM
  Failure.

  White gets a nice position on the left if he plays 1, but ...
  ENDCOM
  B 2 R10
  COM
  ... the checking extension of Black 2 leaves the white stones
  vulnerable and White must defend them. But Black will make profit
  by attacking them.
  ENDCOM
  ENDVAR
  VAR
  W 1 R14
  COM
  Failure.

  If White 1 here, ...
  ENDCOM
  B 2 R10
  COM
  ... Black 2 is still a severe move.
  <=
  ENDCOM
  ENDVAR