EVENT
BOARDSIZE 19
SETUP W D16 D4 F4 K4 O3 O17 L17 
SETUP B C10 C6 Q3 R5 Q11 Q16 P15 
COM
Problem 155. Black to play.  

Kobayashi Koichi used to play the black formation on the right.
Where should Black play next ? 
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B 1 P5
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Black should jump to 1, aiming to attack White at the bottom.
White must defend.
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  VAR
  B 1 C13
  COM
  Failure.

  Black 1 seems like a good point, but ...
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  W 2 P5
  MARK A@R6
  COM
  ... White will press at 2, wiping out Black's moyo. Next, White
  A would be a severe move.
  <=
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  ENDVAR
W 2 O5
COM
If she attaches at 2, ...
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B 3 O6
COM
... Black makes a moyo on the right with 3 ...
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W 4 N5
B 5 P6
COM
... and 5.
<=
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  VAR
  B 5 N6
  COM
  Black 5 here is also a strong move.
  <=
  ENDCOM
  ENDVAR