As Jeff Mann states on his Web site (http://perfectgolfswingreview.net/)
One can see the glass plane resting on Ben Hogan's shoulders. Many golfers have misinterpreted this photo and they have thought that it means that Ben Hogan recommended that a golfer should swing his clubshaft on the plane repesented by the glass plane during the backswing. However, that idea is incorrect and it doesn't represent what Ben Hogan stated in his book. Ben Hogan wasn't referring to the clubshaft when he envisaged this glass plane idea - he was thinking of his left arm. In his book, he stated that a golfer should perform a backswing action that would keep the left arm below the glass plane throughout the entire backswing, and he didn't want the left arm to break through the glass pane during the backswing. In other words, Ben Hogan wanted golfers to avoid a steep left arm movement during the backswing, and he believed that the left arm should get across the shoulder turn angle at the end of the backswing, and that the hands should end up in a position behind the right shoulder. Ben Hogan didn't want golfers to get their hands above the right shoulder and close to the back of the neck as a result of a too-steep arm lifting movement. Ben Hogan stated that one should feel the back of the left forearm brush against the undersurface of the imaginary glass pane in the late backswing as the arms finally reach their end-backswing position.I'm actually surprised by how many golfers still do not understand this concept. Here's a pic of Aaron Baddeley at address and swinging the club and it shows the different planes besides the ones that Hogan drew in his book '5 Lessons.'
There's other planes as well, such as the squared shoulder plane and the turning shoulder plane. In this pic, Baddeley uses in my mind the most commonly used planes, the elbow plane and the right shoulder plane (aka 'turned shoulder plane).
IMO, too many golfers are infatuated with the 'one plane' swing and think that the one plane swing will cure all their ills and that a 'two plane' swing (which Baddeley is operating from in this pic) is inconsistent and requires a lot more timing. Personally, I think most golfers would be just fine if they concentrated on executing a swing that has a flat left wrist at impact and a clubhead lag pressure point. And as long as the club is pointing at the target line at different parts of the golf swing (aka having 'straight' plane lines) the golfer is on their way to being a pretty darn good ballstriker.
Furthermore, I see no evidence that a one plane swing requires less timing and is more consistent and a two plane swing requires more timing and is more inconsistent.
Anyway, the purpose of this post is to look at Homer Kelley's 'plane shifts' as described in 'The Golfing Machine.'
10-7-0. GENERAL Plane Angle Variations are classified according to the shifts in the Plane Angle of the Stroke path. A shift may be made (1) during the Backstroke, (2) during the Downstroke, or (3) at the Top of the Stroke.
So a golfer's plane shifts can be made during the backswing, during the downswing or at the top of the golf swing.
10-7-A. ZERO This classification is included so it can be indicated in a player's preapred Stroke Pattern that one Basic Plane Angle is to be used throughout the stroke without a 'Variation' --- that is, No Shift
Easy enough. The golfer stays on the same plane throughout the golf swing. Hogan used a 'zero shift.' Hogan stays on the elbow plane, Tiger stays on the turned shoulder plane.
10-7-B. SINGLE SHIFT This Shift relates only to the shift from the Elbow Plane Angle to the Turned Shoulder Plane Angle during the Backstroke with a Downstroke on the Turned Shoulder Plane Angle.
A single shift means the golfer goes from the elbow plane to the turned shoulder plane on the backswing and then stays on the turned shoulder plane throughout the downswing. I utilize a single shift swing (http://www.youtube.com/watch?v=1woMtI9s7HE)
10-7-C. DOUBLE SHIFT This involves the return of the Stroke to the Elbow Plane Angle after a Single Shift during the Backstroke.Meaning, the golfer makes a single shift in the backswing...going from the elbow plane to the turned shoulder plane...then from the top of the swing the golfer the golfer returns back to the shoulder plane. Moe Norman is a perfect example and is NOT a 'single plane swing.'
10-7-D. THE TRIPLE SHIFT This Backstroke is the same as for -B and -C above. It starts out on the Elbow Plane Angle and finishes on the Turned Shoulder Plane Angle. It then shifts immediately to the Vertical Downstroke motion of the Turning Shoulder Plane Angle.So it's a single shift motion on the backswing and then at the top of the swing it shifts to the turning shoulder plane on the downswing. Paul Hart (GSED) in Peter Croker's 'TGM Downloads' says that Ray Floyd uses a 'Triple Shift.' I also feel that Zach Johnson looks like a Triple Shifter to me, but I'll ask around to get a better idea.
10-7-E. REVERSE SHIFT As its name implies, it is the exact reverse of the Single Shift. That is, the Shift is from a Turned Shoulder Plane Angle Backstroke to an Elbow Plane Angle Downstroke.Meaning, it's a reverse single shift. Golfer starts out on a turned shoulder plane angle on the backswing and then makes one shift the to elbow plane on the downswing. This is pretty common for golfers and something that Tiger seems to be going to lately. Trevino *might* be considered a reverse shift golfer as well.
10-7-F. THE LOOP The Loop is similar to the Single Shift except that the ShiftSo, this is a move similar to the Single Shift, but the shift goes from the elbow plane to the squared shoulder plane in the backswing (instead of shifting to the turned shoulder plane) and is done with a very obvious in-to-outward looping motion. Sort of like a reverse Fred Couples motion.
is made to the Squared Shoulder Plane Angle and is done with a looping motion of the Clubhead. Knowing how to stay On Plane, per 2-F, will correct for the Flat Shoulder Turn 'Shift' to this steeper Plane --- intentional or not. But the cure is Pivot Correction (See 9-1.)
10-7-G. THE REVERSE LOOP This is similar to the Reverse Shift except that the Shift is made from the Squared Shoulder Plane Angle but also is done with a looping motion of the Clubhead. Handled with skill, this Shift can be very effective.This is pretty much what the title says. It's a backswing that starts off on the squared shoulder plane, which is a pretty upright backswing and then goes to the elbow plane on the downswing.
10-7-H. THE TWIST Here the Backstroke is on the Turning Shoulder Plane Angle, but the Downstroke shifts directly to the Squared Shoulder Plane Angle by an immediate Flat Shoulder Turn with its obvious looping action.This swing loops IN to OUT. Going from the turning shoulder plane to the more upright.
If I had to guess, I would say the Single Shift motion is used the most by golfers, followed by the Double Shift, than the Reverse Shift, and then the Zero Shift. The Reverse Loop Shift, Loop Shift and Twist are probably pretty rare to see executed effectively.