(;
GM[1]
SZ[19]
AW[qf][ql][ol][eq][fq][gp][po][or][pq][qq][qr][ps]
AB[pj][dj][dp][pd][pp][dd][nd][qn][jc][dq][fp][fo][qo][pr][nr][oq][op]
LB[ps:10][nr:9][qr:8][op:7][qq:6][oq:5][pq:4][qo:3][po:2][pr:1]
C[Problem 45. Black to play.  

The game in Problem 41 continued up to the sequence of White 10. Where should Black play next ? ]
(;B[mq]
TE[2]
C[Correct Answer.  

Black must establish a thick position in the lower right by defending tightly with 1. Black's stones are now nearly impregnable, so, with this strong position as a backup, he can aim at White's weak stones on the lower left.  <= ]
)
(;B[mp]
C[How the game continued.  

Black 1 also strengthened the black stones at the bottom, but it still left them a bit thin. ]
;W[mr]
C[White attacked the base of these stones with 2 and ... ]
;B[mq];W[ns]
(;B[lr];W[nq];B[np];W[kq];B[nr];W[md];B[mc];W[nq];B[lq];W[ko];B[mm];W[ml]
C[... she was able to throw the game into confusion with the sequence to 16. Instead of being a strong and forceful threatening force, the black stones on the lower right now had to fight for life. <= ]
)
(;B[kq]
LB[lr:@]
C[Instead of @, Black should have jumped to 5. ]
;W[nq]
C[After the exchange of White 6 ... ]
;B[np]
C[... for 7, Black has a thick position facing the center and it still poses a serious threat to the three white stones on the left. <= ]
))
)