(;
GM[1]
SZ[19]
AW[cd][ce][cg][di][fd][gf][id][ig][jg][kg][md][lh][mi]
AB[dp][pd][pp][eh][ef][de][dd][ec][kd][gh][ih][jh][li][le][me]
LB[gh:1][ig:2][ih:3][jg:4][jh:5][kg:6][li:7][md:8][le:9][lh:10]
LB[me:11][mi:12]
C[Problem 159. Black to play.  

The game in Problem 155 continued with the sequence to the hane of White 12. How should Black continue ? ]
(;B[lj]
LB[jj:B][kh:A]

TE[2]
C[Correct Answer.  

Black should extend to 1, maintaining his dominance in the center. (If White A, Black makes shape with B.) ]
;W[od]
C[If White next switches to the top right by attaching at 2, ... ]
;B[pe];W[pc];B[qc];W[qb];B[oc];W[pb];B[nd];W[qd];B[oe];W[rd]
C[... Black can build a thick position and force White to live in the corner in gote with the sequence to 12. ]
;B[mj]
C[Black 13 is now a thick move, putting enormous pressure on the white stones at the top. <= ]
)
(;B[ki]
C[How the game continued.  

Black drew back with 1. This was passive because ... ]
;W[mj]
C[... it allowed White to take the initiative in the center with 2. ]
;B[nd]
C[Black secured the top with 3 and ... ]
;W[qd];B[qc];W[pe]
LB[qd:4]
C[... White made forcing moves with 4 and 6, ... ]
;B[pc];W[qn]
C[... then made an approach move at the bottom with 8. ]
;B[np]
C[White clearly covets the right side, although her stones there are, at the moment, a bit thin. <= ]
)
)