(;
GM[1]
SZ[19]
AW[cc][dj][dp][fq][jd][nc]
AB[pd][pf][pk][po][pq][jp]
C[Problem 151. Black to play.  

The black and white moyos divide the board. With one move, however, Black can break up White's moyo and wipe out much of it's influence. ]
(;B[dd]
LB[cd:B][dc:A]

TE[2]
C[Correct Answer.  

Making a large-scale moyo from the 3-3 point is unnatural because Black will land a devastating blow in the center of White's position with 1. White will respond with A or B. ]
;W[cd];B[de];W[eb];B[ce]
C[After the moves to 5, Black's stones are quite resilient and cannot be easily attacked. ]
;W[fd]
C[If White 6, ... ]
;B[fe]
C[... Black attaches at 7. <= ]
)
(;B[ec]
C[Black is under attack.  

Playing one line deeper with 1 is bad ... ]
;W[de]
C[... because Black will come under a severe attack with 2 ... ]
;B[hc];W[jc]
C[... and 4. <= ]
)
(;B[ed]
C[Failure.  

If Black 1 here, ... ]
;W[de]
C[... White 2 is again the vital point. <= ]
)
)