EVENT
BOARDSIZE 19
SETUP W D16 H17 Q18 P17 Q16 Q15 P14 R5 R7 E3 F4 K3 N3 
SETUP B L17 R18 R17 R16 R15 R13 Q17 Q3 P4 Q6 C10 C4 D5 
COM
Problem 51. Black to play.  

The middle game has begun. How should Black attack ? 
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B 1 O17
USER
CORRECT ANSWER
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COM
Correct Answer.

Black expands his position with 1 ...
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  VAR
  B 1 R4
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  Failure.

  If Black immediately attaches with 1, ...
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  W 2 N17
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  ... White can make shape by taking the vital point of 2. The
  black stone at the top is now isolated and weak.
  <=
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W 2 P18
B 3 O16
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... and 3, leaving White's stones heavy.
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W 4 P16
B 5 M14
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He then makes shape with 5, ...
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W 6 P12
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... forcing White to escape with 6.
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B 7 R4
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Next, Black attaches with 7. White's stones are now unsettled,
while Black's are secure.
<=
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