(;
GM[1]
SZ[19]
AW[md][nc][oc][pc][qb][cn][gd][mc][ld][lf][dg]
AB[jp][jd][pj][dj][dp][pd][pp][dd][od][nd][ne][qc][cl][rc][jc][lc][lb][fp]
TR[lf]
C[Problem 11. Black to play.  

White jumped out into the center with the marked stone in Problem 7, threatening Black's moyo on the right and the four black stones at the top. How should Black respond ? ]
(;B[jf]
TE[2]
C[Correct Answer.  

Black must jump to 1, strengthen his four stones. ]
;W[lh]
C[White answers by jumping to 2. ]
;B[gf]
C[Next, Black attacks on the left with 3 and ... ]
;W[ee];B[ed];W[fe];B[de];W[fg]
C[... White makes shape with the sequence to 8. ]
;B[jh]
C[The black stones at the top still have to escape, so Black jumps to 9. ]
;W[og]
C[If White 10, ... ]
;B[qg]
C[... Black is satisfied to defend at 11. ]
(;W[df]
C[If White 12 next, ... ]
;B[gc]
C[... Black can link up ... ]
;W[hc];B[gb]
C[... with the sequence to 15.  <= ]
)
(;W[nq]
LB[nq:??]
C[Continuation after the Correct Answer.  

White plays elsewhere (White ?? is necessary here to get "Black to move") ... ]
;B[ef]
C[After Black 11 in the Correct Answer, Black can take the territory on the left side ... ]
;W[ff];B[eg];W[eh];B[df];W[fh];B[ch]
LB[dh:B][cg:A]
C[... with the sequence to 19. The points A and B are miai for Black. <= ]
))
(;B[ng]
C[How the game continued.  

Black jumped to 1 and, ... ]
;W[jf]
C[... when White capped at 2, ... ]
(;B[gb]
C[... slid to 3. ]
;W[fc]
C[The sequence ... ]
;B[fb];W[ec];B[cc]
C[... to Black 7 followed. This was bad for Black.  <= ]
)
(;B[if]
C[Black should have attached at 3 here. ]
(;W[ig]
C[If White haned at 4, ... ]
;B[hf];W[je];B[hd]
C[... the sequence to Black 7 would most likely be played and Black would end up with good shape.  <= ]
)
(;W[jg]
LB[ig:@]
C[Therefore, White should have simply extended to 4 (instead of @).  <= ]
)))
)