EVENT
BOARDSIZE 19
SETUP W B16 D16 F17 D2 F3 J3 Q4 P3 P8 R8 M17 N15 
SETUP B C14 E14 D10 D4 C3 D6 R10 P10 P16 R16 K17 L16 
MARK A@M17 B@L16 C@N15
COM
Problem 41. Black to play.  

How should Black continue after the sequence to White C ? 
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B 1 O17
MARK A@M16
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Black should first defend the corner with 1, threatening to take
the territory at the top by playing at A.
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  VAR
  B 1 M16
  COM
  Failure.

  Cutting trough with Black 1 ...
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  W 2 N16
  B 3 N17
  COM
  ... and 3 is crude.
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  W 4 O17
  B 5 N18
  W 6 P17
  MARK A@M18
  COM
  Note that after White 6, White threatens to capture the two marked
  stones by playing A.
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  B 7 M18
  COM
  Black can capture one stone with 5 and 7, but ...
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  W 8 Q16
  B 9 Q15
  W 10 Q17
  COM
  ... Black's corner in the upper right has been destroyed.
  <=
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  ENDVAR
W 2 M16
COM
White defends at this point with 2. but ...
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B 3 L14
COM
... Black continues the attack with 3 ...
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W 4 N13
B 5 M12
COM
... and 5. The white stones are in trouble.
<=
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