Courtesy of my California student, Doug, here's a four-minute clip from our all day-session last winter. The focus is on the Delivery Path of the Hands and precisely how the Straight Line Path can be determined. Along the way I touch on Plane Line Tracing and the Flying Wedges.
Note: When I discuss the 'Golf Machine Stroke' I mention beginning 'with the Left Wrist Flat, Level and Vertical. I am not suggesting this is the preferred Address Position. Instead, I am referencing its Impact Fix alignment and establishing the Plane of the Right Forearm to direct the Hands on the Backstroke's Right Forearm Takeaway.
Also, when discussing the Right Forearm Flying Wedge, I concentrate on the Cocking (Vertical Motion) of the Right Wrist as the #1 'bad guy' because Doug's Overswing was causing some problems there. However, once the Impact Fix degree of Bend has been achieved (usually at the Top), then there must be no additional Bending or Flattening (Horizontal Motion) of that alignment until the end of the Follow-Through.