(;
GM[1]
SZ[19]
AW[ec][dc][cd][cf][qf][rf][qd][qc][kr][nq][no][pr]
AB[dp][pd][pp][ed][fd][fc][jd][pc][pe][og][qh][kp][qq][pn]
LB[nq:1][kp:2][no:3][pn:4][pr:5][qq:6][kr:7]
C[Problem 143. Black to play.  

In this problem, the same joseki as in Problem 142 has been played. Where is the vital point for Black ? ]
(;B[nm]
TE[2]
C[Correct Answer.  

Black 1 is the focal point for building a moyo. ... ]
;W[fp];B[dn]
TR[kp]
C[... Black should be willing to sacrifice his marked stone to expand his moyo in the center. <= ]
)
(;B[gq]
C[Failure.  

Extending to  Black 1 is aimless. ]
;W[nm]
C[White jumps to 2 and Black no longer is able to make a moyo in the center. <= ]
)
)