EVENT
BOARDSIZE 19
SETUP W D16 D13 C6 D4 K4 O3 O2 O5 P15 
SETUP B O7 Q6 Q4 P3 R10 Q14 R16 P17 J16 F17 
MARK 2@Q14 1@P15
COM
Problem 152. White to play.  

Black 2 is the usual answer to the capping move of White 1. White's
next move in common sense, but there are many variations you
must consider.  
ENDCOM
W 1 O17
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

White should attach ...
ENDCOM
B 2 O18
  VAR
  B 2 P16
  COM
  Don't be afraid if Black pushes up ...
  ENDCOM
  W 3 O16
  B 4 O15
  MARK 2@P16
  COM
  ... and cuts with 2 and 4.
  ENDCOM
  W 5 N15
  B 6 O14
  W 7 M16
  MARK \t@P15 5@N15
  COM
  White makes sabaki with 5 and 7, fully using the marked stone.
  <=
  ENDCOM
  ENDVAR
  VAR
  B 2 Q17
  COM
  Drawing back with 2 is a quiet move.
  ENDCOM
  W 3 N15
  MARK A@L17
  COM
  However, after 3, White is satisfied because she has erased Black's
  moyo. Moreover, White can still aim at the extension of A.
  <=
  ENDCOM
  ENDVAR
  VAR
  B 2 O16
  COM
  If the ladder favours Black, ...
  ENDCOM
  W 3 P16
  B 4 Q17
  MARK 2@O16
  COM
  ... 2 and 4 are strong moves.
  ENDCOM
  W 5 N17
  COM
  White would have to extend to 5 and ...
  ENDCOM
  B 6 N16
  MARK 5@N17 2@O16
  COM
  ... Black would push along at 6. White's position is not good.
  However, the ladder favours White here, so she would play 5 at
  6 and capture the stone at 2.
  <=
  ENDCOM
  ENDVAR
W 3 P18
MARK 1@O17
COM
... and cut with 1 and 3.
ENDCOM
B 4 Q18
  VAR
  B 4 O16
  COM
  Big profit.

  If Black is determined to get outside influence, the can play
  4 ...
  ENDCOM
  W 5 N17
  B 6 P16
  COM
  ... and 6.
  ENDCOM
  W 7 Q18
  COM
  White gets a big profit at the top. This is not a good result
  for Black.
  <=
  ENDCOM
  ENDVAR
W 5 P16
B 6 P19
COM
If Black captures with 6, ...
ENDCOM
  VAR
  B 6 Q17
  MARK \t@P16
  COM
  Black connects.

  If Black connects with 6 in answer to the marked stone, ...
  ENDCOM
  W 7 N18
  COM
  ... White ataris with 7.
  ENDCOM
  B 8 P19
  COM
  This is a good result for White, but she must be careful where
  she makes her next move.
  <=
  ENDCOM
  ENDVAR
W 7 Q17
COM
... White ataris with 7 and, ...
ENDCOM
B 8 P18
COM
... after Black connects at 8, ...
ENDCOM
W 9 N17
COM
... extends to 9.
ENDCOM
B 10 Q16
COM
Black defends with 10 and ...
ENDCOM
  VAR
  B 10 N15
  COM
  The vital point, but ...

  Before defending on the right, Black could play on the vital
  point with 10.
  ENDCOM
  W 11 M15
  B 12 N14
  W 13 N16
  MARK 11@M15
  COM
  After White 11 and 13, ...
  ENDCOM
  B 14 Q16
  MARK B@S18 A@R17
  COM
  ... Black must go back and defend with 14. This result is better
  for White than the on in the Correct Answer. If Black omits 14,
  the aji of White A - Black 14 - White B remains.
  <=
  ENDCOM
  W 15 M14
  ENDVAR
W 11 N15
COM
... White makes good shape with 11. This is a middle-game joseki.
<=
ENDCOM