EVENT
BOARDSIZE 19
SETUP W D16 D14 D10 D4 H3 H5 K5 O7 Q6 R6 S6 S7 S5 T6 R4 R3 S3 T4 Q17 R17 
SETUP B K3 M4 Q3 Q4 Q5 R5 P6 P7 P8 Q7 R7 R8 S8 P17 Q16 F17 K16 Q14 
MARK \t@R17
COM
Problem 96. Black to play.  

White extends with the marked stone, how should Black respond
? 
ENDCOM
B 1 P18
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

When Black descends to 1, ...
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  VAR
  B 1 R16
  COM
  Failure.

  Black can get the corner territory by blocking with 1 ...
  ENDCOM
  W 2 P18
  B 3 O18
  COM
  ... and 3, but, ...
  ENDCOM
    VAR
    B 3 O17
    MARK 2@P18
    COM
    Failure.

    If Black extends to 3 in response to White 2, the result is the
    same as in the Failure Diagram in Problem 92.
    <=
    ENDCOM
    ENDVAR
  W 4 O17
  B 5 P16
  W 6 N18
  B 7 Q18
  W 8 O19
  B 9 R18
  W 10 M16
  COM
  ... after 10, White's stones are secure and the black stones
  at the top left are vulnerable.
  <=
  ENDCOM
  ENDVAR
W 2 S15
B 3 S14
W 4 R15
B 5 R14
W 6 Q15
B 7 P15
W 8 R16
B 9 P16
W 10 Q18
COM
... the sequence to 10 is inevitable. White is alive in the corner,
but ...
ENDCOM
B 11 F15
COM
... Black ends up with a vast moyo when he jumps to 11.
<=
ENDCOM