EVENT
BOARDSIZE 19
SETUP W D16 D14 C8 D6 D5 D4 D3 K4 N4 N5 O5 R11 Q10 P10 P9 O12 R14 
SETUP B C3 C4 B6 C6 C2 O4 P4 Q3 Q6 Q8 Q9 R10 S10 S15 P14 Q16 K16 F17 
MARK A@G15 B@C7 C@P7
COM
Problem 138. White to play.  

White has mapped out a huge moyo at the bottom. How should she
now play ? 
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W 1 P7
USER
CORRECT ANSWER
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COM
Correct Answer.

Before doing anything else, White should peep at 1.
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  VAR
  W 1 G15
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  Failure.

  If White jumps to 1, threatening Black's territory at the top,
  ...
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  B 2 D7
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  ... Black will cut through with 2 and ...
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  W 3 C7
  B 4 E7
  W 5 D10
  B 6 F5
  W 7 G3
  B 8 G7
  W 9 H4
  B 10 F10
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  ... wipe out White's moyo with the sequence to 10. (See Get Strong
  at Joseki 3, Problems 153, 158, 163, and 168.)
  <=
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  ENDVAR
B 2 P6
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Black must defend with 2 ...
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W 3 O7
B 4 Q7
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... and 4 or else White will wipe out Black's territory on the
right.
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W 5 C7
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Next, White protects her weakness at 5.
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B 6 J12
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If Black 6, ...
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W 7 G15
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... White plays 7.
<=
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