The Face to Path Relationship and Hogan's "Plane of Glass"

Many golfers begin their journey with a ball flight that resembles a banana, slicing with a curve from left to right for the right-handed player. Their imagined cure is logical: aim left and swing even more to the left and the ball won't spin as much. Unfortunately, this remedy only serves to increase the amount of curve on the shot. Why is this?

Hogan's "Plane of Glass" is an excellent illustration of a how to begin to cure a slice. In the book, "The Five Fundamentals of the Modern Swing" by Herbert Warren Wind and Ben Hogan, the illustrator, Anthony Ravielli drew a plane of glass extending from the ball through Ben Hogan's neck, as illustrated above. Swing "over the top" with an open club-face, break the plane of glass and the ball slices. However, swing "under" the plane of glass, shallowing the path at which the club-head is now approaching the ball ( slightly from inside to out) and if the face closes to that path you have a draw!

When the face of the club is "open" to the path the club is travelling on this "glancing blow" creates side spin. The spin is energy transferred in a different direction than the club face is pointing and depends on how much the club is open or closed to the path. Ideally, envision a semicircle overhead where the direction of the path of the club is traveling on is square to the path (as illustrated below) The cool thing with today's technology is the Face/Path relationship is improved with today's launch monitors.

Why does a driver "slice" more than a wedge? Almost all golf shots begin with "backspin". But a wedge has so much more backspin relative to a driver that spin actually lessens the distance traveled as the spin sends the ball high in the air. The increase in backspin relative to a drive overtakes the side-spin, resulting in less curve relative to distance traveled.

By utilizing a launch monitor the face path relationship is easily improved. I ask my students to work within the 2's, 2 degrees open or closed or 2 degrees inside to out or out to in. That way they reduce the side-spin on their shots and help them to shoot lower scores!