(;
GM[1]
SZ[19]
AW[cb][dc][ec][hc][ph][qq][qp][qn][rn][dq][co][eo][bl][bk][ck][ci][di][ei][fn][gn][hp][iq][jq]
AB[bc][cc][dd][ce][fe][oc][qd][ql][om][po][pp][pq][cl][dj][ej][fj][el][en][hl][in][jp][kp][kq]
TR[ph]
C[Problem 76. Black to play.  

White enters Black's sphere of influence with the marked white stone. How should Black attack ? ]
(;B[oi]
TE[2]
C[Correct Answer.  

The shoulder hit of Black 1 not only attacks the invading white stone, it also maps out a  large moyo. ]
(;W[oh]
C[If White pushes out with 2 ... ]
;B[nh];W[ng]
C[... and 4, ... ]
;B[mg]
LB[mh:A][nh:3]
C[... the two-step hane of Black 3 and 5 is severe. Simply extending to A with 5 is also good, and this move avoids complications. <= ]
)
(;W[qe]
C[Continuation.  

In the game, White forced with 2 ... ]
;B[pd];W[pi]
C[... and 4, ... ]
;B[pj];W[of]
C[... then jumped to 6. ]
;B[re]
C[Black made his corner thick with 7, then ... ]
;W[mf];B[lh]
C[... followed it up by mapping out a large moyo with 9 ... ]
;W[kf];B[jg]
C[... and 10. Note that White's moves have gained her no territory, while each of Black's have expanded either his moyo or secured the corner. <= ]
))
(;B[og]
TR[ph]
C[Failure.  

Attacking the marked stone with the shoulder hit of 1 is the wrong direction. ]
;W[oh];B[nh];W[oj]
C[Black gains no territory with these moves and he drives the white stones into his potential moyo. It is unreasonable to expect to kill the white stones in such an open space, especially since Black's stones in the lower right are thin. <= ]
)
(;B[nh]
C[Failure.  

Although capping is a good way to attack in many positions, Black 1 is bad. ]
;W[oi];B[ni];W[ok]
LB[nj:B][pl:A][oi:2]
C[The result after White 2 and 4 is similar to the preceding diagram. White is now aiming at A, so Black must defend. Therefore, White will be able to play on the vital point of B. ]
)
)