(;
GM[1]
SZ[19]
AW[dc][dp]
AB[pp][pd]
C[Problem 1. Black to play.  

Black has made a niren-sei formation on the right. If Black wants to play on the left side, which approach move should he make ? ]
(;B[de]
TE[2]
C[Correct Answer.  

Black usually plays the one-space high approach move at 1. This move is preferred because White does not have a good pincer against Black 1 in relation to his marked stone in the lower left. <= ]
)
(;B[ce]
C[The low approach.  

If Black plays a low approach with 1, ... ]
(;W[dh]
C[... White pincers at 2. ]
;B[df];W[fd];B[bc];W[jc]
C[If the joseki to 6 follows, the white stone at 6 reduces the influence of Black's star-point stones on the right. <= ]
)
(;W[ci]
TR[dp]
C[The three-space pincer.  

The three-space pincer of White 2 is a good extension from White's marked stone below. ]
;B[dd];W[ec];B[cc];W[cb];B[bc]
C[Black would most likely settle his stones with the sequence to 7, but ... ]
;W[hc]
C[... then White 8 would reduce the influence of Black's star-point stones on the right. <= ]
))
)