(;
GM[1]
SZ[19]
AW[ed][fd][fc][ef][eh][ld][pp][dp][fp]
AB[cd][dc][ec][cf][hd][nd][qd][cq][bp][cn]
LB[jd:A][hf:C][ie:B][lf:D]
TR[nd]
C[Problem 150. White to play.  

Black has just played the marked stone. How should White take control of the situation at the top ? ]
(;W[ie]
TE[2]
C[Correct Answer.  

White should play the shoulder hit of 1. Black will now find it hard to escape with his stone at the top. <= ]
)
(;W[jd]
C[Failure.  

If White plays 1 here, ... ]
;B[hb]
LB[hf:A]
C[... Black jumps down to 2, threatening to link up to his stones on the left, then jumps to A. <= ]
)
(;W[hf]
C[Failure.  

If White caps with 1, ... ]
;B[jd]
C[... Black can jump to 2. <= ]
)
(;W[lf]
C[Failure.  

White plays on a large scale when she jumps to 1, ... ]
;B[hg]
C[... but when Black jumps out into the center, White finds her stones at the top split apart. ]
;W[jp]
C[White plays 3 to restore the territorial balance, but ... ]
;B[jd]
C[... Black secures his stones with 4 ... ]
;W[lb];B[jf]
C[... and 6. White has a lost game. <= ]
)
)