(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]

;B[qd]
;W[dp]
;B[oc]
;W[rd]
;B[qe]C[This move is the way to sacrifice the corner for the outside. The move you played in the game gives white the option of settlling the shape on the outside.]
(;W[qc]
(;B[re]
;W[pc]
;B[od]
;W[rb]C[ko for the corner, and black takes the outside. ])
(;B[pc]
(;W[qb]C[black can also play like this, but I prefer S15 instead of q17.]
;B[re]
;W[sc])
(;W[re]C[It gives white this option aswell]
;B[rc]
;W[qb]
;B[rb]
;W[qf]C[This is why I prefer the first variation.])))
(;W[re]
(;B[qf]
;W[qc]
;B[pc]
;W[qb])
(;B[rc]C[There's still this move, if black decides he wants to corner after all.])))