ONE PLANE GOLF SWING
Setup
The spine angle is more bent
over at address allowing the shoulders to rotate on a steeper plane.
This, in turn, allows the club to swing up. Ben Hogan, the classic
one planer, stood more erect at address and then swung his shoulders
on a steeper plane during his swing. Jim Hardy advocates the hands
be under or just inside the chin at address.
Vijay Singh has a bit steeper spine angle than David Toms and has
his arms out away from his body a bit more. This sets the golfer up
to have a more "around" swing path.
Backswing
In the one plane swing, the
arms will swing up slightly to a position where they are on plane
with the shoulders at the top of the swing. There are far fewer "moving
parts" because the left arm never leaves the chest to swing up
on a steeper plane. Because the swing is more "around" than
"up", the body may stay more to the left with less lateral
shift, if any, to the right. This reduces the need to have a large
slide back toward the target during the transition. The key in the
one plane swing is swinging the arms around behind the body rather
than lifting of the arms in front of the body. Ben Hogan advocated
that the right leg not move back at all during the backswing, keeping
the body very centered throughout the swing.

Vijay swings the club more around on a more natural swing arc. His
arms have done nothing independent here, they are simply following
his body's lead. Hardy would rather see the club closer to the right
thigh at this point with the left arm angled more in rather than straight
down the line.

Vijay's left arm and shoulder match up very much on the same plane
at the top. But nobody matched up as well as Ben Hogan. Hogan's left
arm and shoulders were perfectly on plane, exactly parallel with each
other, while Vijay is slightly above. Note how much more upright David
Toms' body is compared to Vijay. Singh has his shoulders much more
out over his toes, a trademark of the one plane swing. Below is a
picture of me at the top of the swing hitting a mid iron.

Transition
Because your arms are always
on plane and never lift, there is no need to wait for them to drop.
Your body can begin to rotate back toward the target as aggressively
as you like and the arms should simply follow. The natural instinct
at the top of the swing is to get the club head back to the ball as
fast as possible in order to strike it with authority. Of course,
this is the key detriment to swinging on two planes where you simply
must create some sort of delay during the downswing to let the arms
fall back down on plane in a position to strike the ball. Hardy points
out that in a one plane swing, all you do from the top is rotate the
body back to the left after setting your weight more on your left
side. Everything rotates together, reducing the dependency on timing
and rhythm to blend the upright swinging of the arms and the flatter
turning of the body. Unfortunately, many golfers swing their arms
"up" on the backswing and then try and rotate their bodies
back to the left as hard as they can. In essence, they are combining
characteristics of the two swings, which doesn't work and creates
the dreaded "over the top" move creating a pull slice.

Vijay gets back parallel to the plane earlier than Toms, and then
matches up perfectly halfway down.

Back on plane, but Hogan never strayed far from
it. Vijay stays closer than most today.
Steve Flesch's transition is one of the best
in the business. His aggressive body rotation back to the target creates
the look of him hanging on his front leg, but this is simply not true.
His body began moving back to the target before his club reached the
top of the swing, creating a tremendously dynamic position. Because
his arms are on plane, he can simply swing back to the target with
no waiting.
Downswing
In the one plane swing, the
arms, club and shoulders are already on the proper plane, allowing
the golfer the freedom to simply rotate the body back to the left.
With the left arm velcroed to the chest, the body can rotate as hard
it likes without ever worrying about trying to control the arms. It
is important that the golfer properly use his body to swing the club
and not the arms. Golfers who are accustomed to swinging their arms
to generate power often find this one of the biggest challenges. No
longer requiring the arms to try and control the club, the golfer
can do what he instinctively wants from the top of the swing - swing
hard. You'll quickly find that this swing will feel more natural,
more like hitting a baseball off a tee. A downswing mantra would be
"swing left".

Vijay is not in a classic one plane impact position here according
to Hardy, but he has done an excellent job of returning the club to
its original position established at address. Vijay's swing, like
most golfers on tour, is a bit of a hybrid. Vijay works hard at keeping
his left arm glued to his chest throughout the swing. You've no doubt
seen him swing with a golf glove under his left arm. That is a major
key to the one plane swing and helps the body stay more in control
of the club and make a full turn on the backswing.
The principles that Jim Hardy has come up with can act as a guideline
for golfers to help understand the concept of the two swings. As you
learn more about the two swings, you will see that most professional
golfers exhibit traits from both swings, although you will benefit
from learning the principles and choosing one swing or the other.