(;
GM[1]
SZ[19]
AW[cc][df][dq][dr][er][fr][fq][gp][hq][dm][cl][em][cn][co][cp][pb][nc][kc]
AB[gq][eq][ep][fp][dp][do][dn][cm][bm][bp][bq][cq][nq][pp][qo][pd][qc][qf]
LB[df:1]
C[Problem 153. Black to play.  

White makes a large moyo with 1. Black has taken a lot of territory in the three corners, so all he needs to do is to break up this moyo. Should Black play a light erasing move or attack at the base of White's moyo ? ]
(;B[jd]
TE[2]
C[Correct Answer.  

Erase with a shoulder hit. Black is sated with solid territory, so he doesn't need to fight for more. It is sufficient just to erase White's moyo with the shoulder hit of 1. Remember the proverb: 'When you want to erase, hit at the shoulder !' ]
(;W[jc];B[id];W[kd];B[jf];W[ke];B[hg]
LB[lg:A]
C[The moves to 7 are joseki. After this, White will aim to play at A to set up a base from which to attack the right side and the top right corner. <= ]
)
(;W[kd]
C[A successful erasure.  

White could also push up with 2 ... ]
;B[je];W[ke]
C[... and 4, ... ]
;B[jf];W[ib]
C[... then slide to 6. ]
;B[kf]
C[But 7 is a thick move, giving Black influence throughout the board. Black has successfully erased White's moyo and his three corners are still intact. <= ]
))
(;B[dc]
C[The attachment doesn't work.  

Attaching at 1 might also be considered. ]
;W[dd]
(;B[ed]
C[Black hopes to make sabaki with 3, but ... ]
;W[ec];B[db];W[eb];B[de];W[cd];B[fd];W[ce];B[fb];W[cb];B[fc];W[da]
TR[kc]
C[... up to 14, Black's stones have no eyes and are blocked from extending by the marked stone. These4 stones have become a burden on Black. <= ]
)
(;B[ic]
C[An ideal result for White.  

If Black invades at 1, ... ]
;W[gc]
C[... White will attach with 2. ]
;B[ie]
C[All Black can do is to run away into the center with 3, ... ]
;W[ke]
C[... but White continues the chase with 4. By attacking theses black stones, White will be able to make territory. This is an ideal result for White. <= ]
)
(;B[pj]
TR[qf][qo]
C[Good shape, but ...  

Black 1 is a slow and deliberate way of playing and makes an ideal shape with Black's two marked stones. ]
;W[hd]
LB[jd:A]
C[On the other hand, White 2 is also a good point, The result here must be considered even. Clearly, it is better to disrupt White's moyo by playing the moves beginning with the shoulder hit at A. <= ]
)
(;B[ec]
C[Black's stones are heavy.  

Drawing back with 3 is also bad. ]
;W[cb];B[ed];W[de];B[ic]
C[After 7, ... ]
;W[gc]
C[... White invades at 8, and ... ]
;B[gd];W[hc];B[hd];W[ib];B[id];W[jc]
C[... the black stones are again heavy after the moves to 14. There is a proverb that says, 'when you want to make sabaki, attach !' In this case, the proverb does not apply. <= ]
))
)