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BOARDSIZE 19
SETUP W F17 C7 D7 E7 F7 F6 B6 B5 C4 C3 D3 D2 Q5 Q4 Q3 P3 P2 M3 P17 Q15 J16 K17 
SETUP B D16 C14 D10 C9 C5 C6 D6 D4 E4 E5 E6 F3 B4 B3 B2 C2 R2 Q2 R3 R4 R6 O3 L16 L17 
MARK A@L17 B@K17 C@L16
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Problem 87. White to play.  

After Black invades at A, White attaches with B, How should White
play after Black stands with C ? 

[You will find a supplement to this Problem Diagram as "Problem 142"]
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W 1 K14
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CORRECT ANSWER
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Correct Answer.

Black's two stones at the top are heavy, so White 1 is the perfect
attacking point.
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B 2 L14
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If Black attaches with 2, ...
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W 3 L13
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... White drives Black's stones toward her position in the upper
right with 3 ...
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B 4 M14
W 5 M13
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... and 5.
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B 6 N14
W 7 O12
B 8 P14
W 9 Q14
B 10 P13
W 11 P11
B 12 Q13
W 13 R11
B 14 R13
W 15 S15
B 16 P15
W 17 P16
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White defends with 17, and Black's stones are in trouble. Next
...
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B 18 K13
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... Black cuts with 18, ...
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W 19 J14
B 20 K12
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... then extends to 20 to get some aji on the outside ...
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W 21 L11
B 22 N16
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... before securing his stones with 22.
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W 23 K11
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White switches to the center ...
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B 24 H13
W 25 J11
B 26 H12
W 27 F15
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... and attacks black's stones with the sequence to 27.
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B 28 E17
W 29 F18
B 30 F13
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After Black 30, ...
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W 31 P7
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... White maps out a moyo in the center with 31.
<=
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