Getting out of the wedge and into parallel (via a wedge christie)

A few weeks ago I wrote about how I teach a wedge turn, the primary fundamental input I focus on, and some reasons why a student might struggle.  You can read that post here.  Following on from that, how do we make wedge turners into parallel skiers?  There's a little step in-between called a wedge christie.  This is when the inside ski of a wedge turn spontaneously matches the outside ski and is parallel.  The key word here is spontaneous.  It is not forced by the skier and can happen at any point during the turn.  It will only happen if the skier is making effective and efficient movements that allow the skis to perform on the snow.