(;
GM[1]
SZ[19]
AW[dc][ce][dp][op][jq][lq][mq][nq][nb][ob][pc][qc][rc][rd]
AB[qp][oq][pq][np][no][lp][pj][jd][mc][nc][oc][pd][qd][re][qf]
LB[qf:12][rc:11][re:10][rd:9][mc:8][nc:6][nb:7][ob:5][oc:4][pc:3]
LB[qd:2][qc:1]
C[Problem 167. White to play.  

White has taken the territory in the upper right corner, completing her profit-oriented strategy. But she must now cut Black's moyo down to size. To find the right move, you need to rely intuition rather than analysis. ]
(;W[lk]
TR[op][mm][lj][kg][no][jd]

TE[2]
C[Correct Answer.  

Before discussing the solution, we will show you how to determine the limits of your invasion. We have marked the line stretching from the outermost black stones (marked) enveloping his moyo. If your move is outside this line, you should have no problems, but it might be not enough to win. If it's inside this line, your stone could end up being captured. You have to find the 'golden mean'.  

It is best to approach outside the line, your answer should be to play 1 towards the bottom. Why ? Compare the top and bottom parts of this moyo. On the lower right, White has a marked stone in place. Another stone played in this area could bring the aji of this stone to life. Therefore, it will be easier to make sabaki in this area. ]
(;B[jk]
C[If Black caps with 2, ... ]
;W[ok]
C[... White plays 3 ... ]
;B[pk];W[ol]
C[... and 5, seeking sabaki. However, all your moves should be natural. Do not make unreasonable moves, trying to trick Black. <= ]
)
(;B[nk]
C[If Black defends with 2, ... ]
;W[li]
C[... White jumps to 3. White's stones are working throughout the board and the limits of the black moyo have been defined. <= ]
))
(;W[kk]
TR[mm][lj][kg]
C[Failure.  

The erasure of White 1 is too shallow. ]
;B[mk]
LB[kk:1]
C[Black 2 hits just the right balance in expanding his moyo. Any wider and Black would be overextended. White 1 cannot be considered a good erasure <= ]
)
(;W[mk]
TR[mm][lj][kg]
C[Failure.  

In contrast, White 1 is too deep. ]
;B[kk]
C[Black would immediately cap at 2. ]
;W[ok];B[pk];W[om];B[pl];W[lm]
C[White's stones are not in danger of being captured, but ... ]
;B[kp]
C[... after Black 8, White has also to worry about her stones at the bottom. <= ]
)
(;W[lj]
TR[mm][kg]
C[Failure.  

White plays 1 one line higher than the Correct Answer. This approaches Black's thick wall at the top, so it doesn't have a good feel to it. ]
;B[jj]
C[After Black 2, it is going to be hard for White to make sabaki. <= ]
)
(;W[li]
TR[mm][lj][kg]
C[Failure.  

Suppose White plays even one more line higher. This is clearly a bad move. ]
;B[jj]
C[After Black 2, it is going to be even harder for White to make sabaki. As the proverb says, 'Don't approach thickness !' <= ]
)
(;W[dk]
C[Failure.  

White 1 is too slow. It breaks the iron rule of not allowing your opponent to perfect his moyo. ]
;B[ij]
LB[jj:A]
TR[mm][lj][kg]
C[Black will play 2 (or just A) and what was before only a moyo has almost become territory. In contrast, White 1 is not a very big move. <= ]
)
)