(;
GM[1]
SZ[19]
AW[dc][fc][hc][eq][dk][dh]
AB[de][fe][he][je][pd][pp]
LB[jc:A][pj:B][kp:D][cp:C]
C[Problem 143. Black to play.  

In the upper left, Black has invested a lot of stones to attack White, but his four stones there aren't taking any territory and he seems to be falling behind. Where should he play to rectify the balance of territory ? ]
(;B[pj]
TE[2]
C[Correct Answer.  

Black should make a sanren-sei on the right with 1, aiming to make a moyo. ]
;W[nq]
C[In the game, Black answered the approach move at 2 ... ]
;B[oo]
C[... with the diagonal move at 3. <= ]
)
(;B[jc]
C[Failure.  

The scale of Black 1 is too small. Also, it is not a serious threat against the white group, so ... ]
;W[qi]
C[... White plays on the right with 2, preventing Black from making a large-scale moyo. <= ]
)
(;B[kp]
C[Failure.  

If Black 1 here, ... ]
;W[qj]
C[... White will play 2. <= ]
)
)