(;
GM[1]
SZ[19]
AW[pm][lq][fq][dq][cr]
AB[pj][dj][dp][pd][pp][dd][np][dn][cq][ip]
LB[pm:1][np:2][fq:3][dn:4][lq:5][ip:6][dq:7][cq:8][cr:9]
C[Problem 72. Black to play.  

Black must decide which joseki to play after White hanes with 9. ]
(;B[eq]
TE[2]
C[Correct Answer.  

Black should atari with 1 ... ]
;W[dr];B[er]
C[... and push through with 3. ]
;W[ep]
C[White cuts at 4 and ... ]
;B[fr];W[fp];B[gq];W[gp];B[hq];W[do];B[cp];W[co];B[bo];W[cn];B[bn];W[cm];B[br]
LB[eo:A]
TR[ip][dj]
C[... the sequence to Black 17 is inevitable. Black gets more than 20 points of sure profit. On the other hand, the influence White gets on the outside is neutralised by Black's marked stones and the possibility of Black cutting at A leaves White with bad aji. <= ]
)
(;B[cp]
C[How the game continued.  

The connection of Black 1 was also joseki, but ... ]
;W[er]
C[... when White played 2 her stones in the lower left hat abundant eye-making potential. ]
(;B[ep]
C[Black's lone stone at the bottom was gradually getting weaker and exchanging Black 3 ... ]
;W[eq]
C[... for White 4 didn't help. See Problem 76 for the continuation. <= ]
)
(;B[lo]
LB[ep:@]
C[Instead of @, Black should have played ... ]
;W[ir];B[qo]
C[... the sequence to Black 5 here. <= ]
))
)