The swing plane is determined by the angle of the club shaft relative to the ball and the ground. The swing is on the proper plan when, during the forward swing, an extension from the butt end of the club intersects the golf ball (not pointing in front of or over the ball). There is no one correct plane, but to have a steep or flat plane means other parts of your swing will need to differ from someone who is “on” plane.
Coaches Kyle & Evan on Swing plane
More on Swing Center:
PGA Professional Jim Roy on the Swing plane
PGA PRofessional Derek hooper with Swing plane drills
Rory mcilroy's swing plane
Backswing Plane drill with piers ward and andy proudman
