D Plane and True Path

[John Graham]

The original way all of us PGA pro's were taught to explain ball flight is as follows. Swing plane controls initial direction and club face angle relative to the plane controls curve. Well it turns out to be incorrect. Visually it makes sense but the science says no.

The club face really controls the initial direction and the curve is still determined by face relative to true path.

Got questions? Let me hear them.

[ January 05, 2009, 01:34 AM: Message edited by: John Graham ]

[John Graham]

Here's a little information each of you need that I provided to you that was dead wrong. D-plane is the answer to the question "How should I aim to hit it around this tree?"

[Otto Cuyler]

John,

I realize you would teach a new player the "ideal" swing path, etc. However, what is your approach for older, established players that have had some success with an unorthodox set up and/or compensating swing plane and/or timing manipulation? There are many of us that did not exactly get the modern day lessons in the late 60's...

Do you optimize what they are already pretty good at or attempt to "fix" it and face a whole new muscle memory experience?

Regards,

Otto

[John Graham]

Originally posted by Otto Cuyler:
John,

I realize you would teach a new player the "ideal" swing path, etc. However, what is your approach for older, established players that have had some success with an unorthodox set up and/or compensating swing plane and/or timing manipulation? There are many of us that did not exactly get the modern day lessons in the late 60's...

Do you optimize what they are already pretty good at or attempt to "fix" it and face a whole new muscle memory experience?

Regards,

Otto

Otto, I am a firm believer that there are many ways to swing a golf club that can produce good shots. Especially for someone that has played many years and had success, I never try to redesign the swing.

John

[John Graham]

Originally posted by John Graham:
Here's a little information each of you need that I provided to you that was dead wrong. D-plane is the answer to the question "How should I aim to hit it around this tree?"

So what is the d-plane? The d-plane is the name of the plane, coined by Theo Jorgensen is the book Physics of Golf, created by the 3d path of the clubhead relative to the ball and the normal to the clubface(clubface angle).

Basically, the ball will start closer to the angle of the club face at the hit than the direction of the path. I probably taught most of you that clubpath determines initial direction and clubface angle relative to path determines curve. I WAS WRONG!!

How many of you have tried to hit a fade around a tree with the info, "point the face where you want the ball to land and aim where you want the ball to start." You did everything correctly and proceeded to hit it right into the tree. In order to get the ball to start left of the tree, the face has to be pointing left of the tree when you hit the ball. If you want it to curve, you still need to swing more left than that to get the face open to the path.

Ok, so how much left do I need to aim?(sorry, all u lefties out there, talkin about a right handed fade) Well it depends on the club you have and how much you need to curve it.

I will be putting together another thread soon about 3d path because it's critical to learning how to aim correctly.

[Otto Cuyler]

That said, I've always felt that every shot could be a good one if properly aimed...

[John Graham]

Ok, so I explained the d-plane in the PGA got it wrong thread. Now, I have to add the 3d path picture to finalize the idea. So to quickly review, d-plane determined by 3d path and face angle. What exactly is the 3d path and how is it different from swing plane.

The main thing to remember is that the golf swing is circularly shaped and it reaches its lowest point in only one place. The line that is tangent to that point is the plane line. An example from Brian Manzella goes like this: "the swing plane is the roof and the plane line is the gutter."

If a person hits a ball before the lowest point, the direction of the 3d path is in to out. After the ball the clubhead is still traveling downward and outward toward the lowest point. Conversely, if the ball is hit after the lowest point, the 3d path is out to in.

So, why does this matter? If you want to hit the ball perfectly straight with an iron shot(and you take your divots after the ball) you need to aim/swing left a certain amount depending on the club. More with short irons, less with long irons and possibly to the right if you hit up on your driver.

Here's a link with some more details:

http://www.johngrahamgolf.com/forum/showthread.php?t=80

Any questions?

[Kevin Thornton]

Coach and others joined,
My general shot shape is a fade and after our last lesson John had me move the ball up in my stance a bit because I have been hitting the ball before the lowest point in my swing. Often times getting my club shoved into an extremely deep divot. Can I then derive that by hitting the ball before my lowest point is one of the causes of my fade?

[John Graham]

Originally posted by Kevin Thornton:
Coach and others joined,
My general shot shape is a fade and after our last lesson John had me move the ball up in my stance a bit because I have been hitting the ball before the lowest point in my swing. Often times getting my club shoved into an extremely deep divot. Can I then derive that by hitting the ball before my lowest point is one of the causes of my fade?

Kevin,

Hitting the ball before the lowest point should occur with all of your irons. Just know that the sooner you hit the ball before the lowest point, the more in to out(relative to the ball) you have swung. There is not direct casuality between large divots and fades. It's more likely that a person would hit a fade if they took deep divots because they have less time to square the face.

In our lesson, we moved the ball up so it was easier to swing more around your body than sliding.

Curves of the ball are always related to clubface angle relative to true path.

[John Graham]

I've received a few calls about this concept asking for more clarity and for information on how this info. can fix a slice.

Let me answer the second question first. This information is only useful in explaining ball flight. It is not designed to fix anything. It is simply answering the question, "Why does the ball do what it does?".

Ok. Let's move on to making it more clear. Tradional PGA instruction states in their "Ball Flight Laws" that the swing path of the clubhead determines the balls initial starting direction and the clubface angle when it hits the ball determines what curve if any will occur. Anytime the clubface is perpendicular to the clubhead path the ball will fly straight. Either straight left, straight or straight right. Curve occurs when the clubface is turned either toe in or toe out relative to the clubhead path. Toed out clubface angles, relative to the path, produce curves to the right and toed in clubface angles, relative to the path, produce curves to the left.

The D Plane is similar except that the club face angle has a greater influence on starting direction than stated in the PGA's "Ball Flight Laws". The easiest way to picture a D plane is to imagine or cut out a right triangle(triangle with a right angle in it). The corner with the right angle will represent the target and either one of the other corners will represent the ball. Hold the triangle on a table upright on an edge(so it looks skinny) with the ball corner closest to you and the target corner away from you. The hypotenuse(the line directly opposite the right angle) and the edge of the triangle on the table is the D Plane. The edge on the table represents the clubheads 3D path(if hit exactly at lowpoint) and the hypotenuse represents the loft of the clubface.

If the hypotenuse is a straight line directly over the edge on the table, that would be a straight shot. If you tilt the triangle to the right, while keeping the ball/target edge on the table, that would represent an open clubface. Tilting it to the left would be a closed clubface. Rotating the ball/target edge on the table to the right would be a clubpath swung to the right and rotating the edge to the left would be a club path to the left(again assuming an impact at exactly lowpoint).

Place the target/ball edge on the seam of the table and hold the triangle upright. Let's assume that the seam is the target line. Rotate the triangle so the target corner is left of the seam and the ball corner is still on the seam. Tilt the triangle to the right so the seam is no longer visiable because it's under the paper. What you are now looking at is the common slice. A 3D path to the left with an open clubface.

Now for the big difference. The PGA's "Ball Flight Laws" state that the ball would start along the target/ball edge and curve to the right. The D Plane states that the ball will start closer to the hypotenuse(clubface angle). This is significantly more of a right start than the PGA's way.

OK. So what does this do for me. Like I said at the beginning of this post, the d plane simply better explains the ball flight and can be used to better aim when you have to curve the ball around something.

Don't forget to read about how the 3D path is figured out in a previous post.



Here's how to read the picture. The colored arrows under the golf ball represent the 3D club path(direction of the strike). The dotted lines on the left are the resulting ball flights if the face is pointing left given those three corresponding colored paths. Solid lines are "square" clubface and dashed lines are open faces.

The other picture is from the PGA's "Ball Flight Laws"

[ January 27, 2009, 10:22 PM: Message edited by: John Graham ]