EVENT
BOARDSIZE 19
SETUP W D17 C14 D4 S3 R5 Q6 
SETUP B L3 O4 Q3 Q8 Q11 R16 P16 
COM
Problem 162. White to play.  

Where should White play in this position ? 
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W 1 K17
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

White should extend to 1.
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  VAR
  W 1 N17
  COM
  Failure.

  White 1 is an overplay.
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  B 2 K17
  COM
  Black is strong on the right, so he can pincer at 2 and ...
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  W 3 N15
  B 4 G17
  MARK 3@N15
  COM
  ... extend to 4 after 3. Black has stabilised his stones at the
  top, but White's are now floating in the center.
  <=
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  ENDVAR
B 2 M17
COM
If Black plays the checking extension of 2, ...
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W 3 K15
COM
... White will exchange 3 ...
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B 4 M15
COM
... for 4, ...
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W 5 D9
COM
... then make a double-wing formation in the upper left. White's
moyo is bigger in scale than Black's.
<=
ENDCOM