(;
GM[1]
SZ[19]
AW[dc][bq][cp][bo][dm][gq][hq][hp][io][jo][kp][kq][jr][kn][qq][qp][po][qk]
AB[ce][ci][cq][dq][ep][gp][go][ho][ko][lo][lp][lq][kr][ls][mr][or][pq][qr][oc][qd]
TR[ci]
C[Problem 80. White to play.  

Black has just played the marked stone. This is a big point, but Black's six stones at the bottom left are still insecure. What should White do ? ]
(;W[fq]
TE[2]
C[Correct Answer.  

White 1 is an important point because it takes away Black's eye shape. Next ... ]
;B[do]
C[Black will first play a forcing move with 2 to avoid being cut into two, ... ]
;W[cm];B[hm]
C[... then jump into the center with 4. Black's stones are vulnerable, but there is not a good way to attack them yet. ]
;W[qh]
LB[fq:1]
C[Therefore, White should take her time and simply play a big point on the right side with 5. White 1 in the Correct Answer not only robs Black of his base, it also ensures that White's group has two eyes. For example, ... ]
;B[ir]
C[... if Black attacks with the sequence Black 6, ... ]
;W[iq]
C[... White 7, ... ]
;B[js]
C[... Black 8, ... ]
;W[jq]
C[... White plays at 9 and she is alive. <= ]
)
(;W[qh]
C[Failure.  

Locally, White 1 is a good move, but ... ]
;B[fq]
LB[iq:A]
C[... Black can secure his stones with 2. Black's prospects are now quite good. If the white stones later need two eyes, White will have to come back to play A, so this bad aji will be a burden. <= ]
)
)