(;
GM[1]
SZ[19]
AW[dd][cp][lq][qo]
AB[eq][pq][po][pl][pd]
C[Problem 153. White to play.  

Black has just attached against the white stone on the lower right side. How should White respond ? ]
(;W[iq]
TE[2]
C[Correct Answer.  

White should extend to 1. This move is both an extension and a pincer. ]
;B[qp]
C[If Black secures the corner with 2, ... ]
;W[dq]
C[... White goes on the attack with 3 ... ]
;B[ep];W[dn]
C[... and 5. <= ]
)
(;W[qp]
C[Failure.  

It is not a good idea for White to try to live in the corner. ]
;B[pp];W[qq];B[qn];W[rn];B[rm];W[qm];B[pn]
C[Black builds a thick wall with the sequence to 8 and, ... ]
;W[rl]
C[... after White 9, ... ]
;B[iq]
C[... Black pincers with 10, making a moyo at the bottom. <= ]
)
)