(;
GM[1]
SZ[19]
AW[dd][dp][fp][jp][nq][nc][kc]
AB[cj][cn][pq][qo][pi][pd][oe]
C[Problem 155. Black to play.  

Kobayashi Koichi used to play the black formation on the right. Where should Black play next ? ]
(;B[oo]
TE[2]
C[Correct Answer.  

Black should jump to 1, aiming to attack White at the bottom. White must defend. ]
;W[no]
C[If she attaches at 2, ... ]
;B[nn]
C[... Black makes a moyo on the right with 3 ... ]
;W[mo]
(;B[on]
C[... and 5. <= ]
)
(;B[mn]
C[Black 5 here is also a strong move. <= ]
))
(;B[cg]
C[Failure.  

Black 1 seems like a good point, but ... ]
;W[oo]
LB[qn:A]
C[... White will press at 2, wiping out Black's moyo. Next, White A would be a severe move. <= ]
)
)