(;
GM[1]
SZ[19]
AW[dc][ce][cn][cp][dq][eq]
AB[ep][fq][fp][jp][pp][pd]
C[Problem 171. Black to play.  

White has made a corner enclosure in the upper left corner. Where should Black now play ? ]
(;B[pj]
TR[jp]

TE[2]
C[Correct Answer.  

Black should make a sanren-sei on the right side with 1. With the marked stone at the bottom, this moyo is like an eagle, spreading its great wings in flight. <= ]
;W[nc]
C[Next, White will approach with 2, ... ]
;B[pf];W[pb];B[qc];W[kc]
C[... the continuation to White 1 is one possibility. ]
;B[pn]
C[At this point, Black will strengthen his position in the lower right with 7. <= ]
)
(;B[qj]
C[Failure.  

Black 1 here is too low, as it would be open to a capping move. <= ]
)
(;B[jc]
C[Passive.  

Black plays 1 in order to neutralise the influence of White's corner enclosure in the upper left corner, but this move is dubious. ]
;W[qj]
C[White will play 2 ... ]
;B[qm];W[qg]
C[... and 4 to stake out a position on the right side. Of course, we can't say that Black's position is bad, but it is going to be a long, hard game for him. <= ]
)
)