(;
GM[1]
SZ[19]
AW[ef][dg][hd][hb][hf][nc][nd][cn]
AB[jp][jd][pj][dj][dp][pd][pp][dd][fd][eg][oc][jf][pf][dm][fp]
TR[ef]
C[Problem 33. Black to play.  

How should Black respond to the marked white stone ? ]
(;B[df]
TE[2]
C[Correct Answer.  

Black is strong around here, so he shouldn't be afraid to crosscut with 1. ]
;W[ff]
C[White extends towards her stones at the top with 2 and ... ]
;B[cf]
C[... Black descends to 3. ]
;W[dh]
C[Since the ladder is unfavourable for White, she must extend to 4. ]
;B[fg];W[ei];B[gg];W[gf];B[gi]
C[After Black 9, White finds her three stones on the left under attack. ]
)
(;B[ff]
C[Variation.  

Black could also hane at 1. ]
;W[fg]
C[White ataris with 2 ... ]
;B[eh];W[fe]
C[... and 4, but ... ]
;B[ee]
C[... Black 5 is a double atari. ]
;W[gf]
C[White captures with 6, ... ]
;B[df];W[ff]
LB[df:7]
C[... then connects with 8 in answer to Black 7. ]
;B[cf]
LB[dh:B][ei:A]
C[Black descends to 9 and has secured the territory there. If White A, Black will simply secure the white stone with B. <= ]
)
(;B[cf]
C[How the game continued.  

Black 1 was a bad move. ]
;W[df]
C[It induced White to connect with 2, rendering the lone black stone useless. ]
;B[ce];W[cg]
C[White got a thick position on the outside, ... ]
;B[fb]
C[... while Black took the corner territory. ]
;W[ec]
C[White exchanged 6 ... ]
;B[dc]
C[... for Black 7 to leave some aji behind. <= ]
)
)