EVENT
BOARDSIZE 19
SETUP W D16 D17 D14 C12 B13 C5 D4 G3 K3 S4 S6 T6 T7 R7 R8 S8 R9 R10 Q10 R11 S11 R12 R16 S16 R19 Q19 Q18 Q17 P17 P16 P15 N18 N17 M17 L17 L16 L18 K18 H18 H10 O9 
SETUP B B12 C10 C7 P3 R4 R6 R5 S5 T5 S12 T13 S14 S15 R15 Q15 Q16 R17 S17 R18 S19 O15 O14 N16 M16 O18 J18 J17 K17 K16 K15 L15 F17 F15 G11 Q9 P9 P10 P8 Q11 Q12 
MARK \t@H10
COM
Problem 111. Black to play.  

White has just played the marked stone in an attempt to reduce
Black's moyo. What should Black do ? 
ENDCOM
B 1 G10
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Black should exchange 1 ...
ENDCOM
W 2 H9
COM
... for 2, ...
ENDCOM
B 3 J4
COM
... then lean on White's stones at the bottom with 3 ...
ENDCOM
  VAR
  B 3 E3
  COM
  Failure.

  The game continued with Black 3 ...
  ENDCOM
  W 4 D3
    VAR
    W 4 E4
    MARK 3@E3
    COM
    White's best strategy.

    After Black invaded at 3, White should force Black to live in
    the corner ...
    ENDCOM
    B 5 F3
    W 6 G4
    B 7 C3
    COM
    ... with the sequence to 7. White ends in sente, so her two stones
    in the center can now easily escape; Black's moyo has been erased.
    <=
    ENDCOM
    ENDVAR
  B 5 D2
  COM
  ... and 5. These moves were not good because it gave White a
  chance to rescue her two stones in the middle.
  ENDCOM
  W 6 C2
  B 7 G4
  COM
  Black resumes the attack with 7.
  <=
  ENDCOM
  ENDVAR
W 4 J3
B 5 G4
COM
... and 5.
ENDCOM
W 6 H4
B 7 H5
W 8 H3
COM
After the sequence to 8, ...
ENDCOM
B 9 F8
COM
... Black can play 9, and the two white stones in the center
are trapped inside Black's moyo.
<=
ENDCOM