(;
GM[1]
SZ[19]
AW[pq][eq][cb][db][cc][cd][de][ce][ec][fc][fb]
AB[qd][cp][do][ci][dc][dd][ed][ee][eb][gd][gf][df]
C[Problem 101. White to play.  

The joseki in the upper left corner has come to a pause. White has taken profit, but Black has thickness in the center. What should White do next ? ]
(;W[gp]
LB[fp:A]

TE[2]
C[Correct Answer.  

Although it is important to quickly make an approach move or a corner enclosure in the fuseki, White 1 is an urgent move that must be played before any other. It is played to counter Black's thickness at the top and to prevent him from pressing at A. <= ]
)
(;W[qo]
LB[od:A]
C[Failure.  

If White makes a corner enclosure at 1 or an approach move at A, ... ]
;B[fp]
C[... Black will immediately play 2 ... ]
;W[gq];B[hp]
C[... and 4, and an enormous moyo comes into being on the left. The moves to Black 4 are a joseki. (See Problem 49 in Get Strong at Joseki 1.) ]
)
)