(;
GM[1]
SZ[19]
AW[cc][cd][de][ci][cl][dq][qj]
AB[cb][dc][eb][fd][pp][pd][co]
TR[co]
C[Problem 108. Black to play.  

White is strong on the upper left side, so what should Black do about his marked stone in the lower left ? ]
(;B[gq]
TE[2]
C[Correct Answer.  

Black should make a counterpincer with 1. ]
;W[ep]
C[When White makes the diagonal move of 2, ... ]
;B[jq]
TR[co]
C[... Black can extend to 3, taking up a position at the bottom. By treating the marked stone lightly, Black puts the burden of what to do about this stone on White. ]
;W[dn]
C[If White next plays 4, ... ]
;B[qm]
C[... Black will extend to 5. <= ]
)
(;B[fo]
TR[cl]
C[Failure.  

Against the two-space pincer of the marked white stone, Black 1 is the usual move, but White is strong on the left side, ... ]
;W[gq]
C[... so White will extend to 2, making territory while keeping up the pressure on Black. <= ]
)
)