A Golf Shot in detail...

Hello all,

I thought it might be helpful for some people to post up a swing, along with the numbers taken from a launch monitor, and add some diagrams of the 3D shot components.

The 240fps Video Clip is myself hitting a driver one morning in March 2012 at the Vancouver Golf Club's driving range, when snow flurries (visible in the background) discouraged one of my students from showing up, I tried to make use of the extra time.  While it seems important to include video to give everybody a complete picture, I'd like to point out how difficult (impossible) it is to obtain the shot's specs (Plane, Path, Face, D-Plane, and Launch numbers) by visual-only confirmation.  You'd need doppler radar based machines to have an accurate idea.

Here is the ball flight and swing numbers from a Flightscope Screenshot (yes, video and screenshots were from the exact same swing.

Vertical Plane:   47.8°
Horizontal Plane:   4.6°L

Vertical Path/Angle of Attack:   +1.0°
Horizontal Path/Club Path:   5.5°L

Vertical Face/Dynamic Loft:   9.3°
Horizontal Face/ Face Angle:   3.8°L

3D Spin Loft:   8.7°
Spin Axis:   5.5°R

Vertical Launch:   10.6°
Horizontal Launch:   3.5°L

Club Head Speed:    106.2 mph (cut me some slack, it was cold out...)
Ball Speed:    153.5 mph
Smash Factor:    1.45
Spin Rate:    2890 rpm

Here are some still images from my 3D Modelling of this particular shot:

Down The Line view:

Face On view:

Overhead view:

I'll start by pointing out some of the expected relationships between some of these numbers.  Even though my swing's Plane is aligned 4.6° left of the target line, since I'm hitting slightly up on the ball (+1.0°), my club's Path is slightly more left, arriving at 5.5°L.  My natural tendency is to hit down with the driver, but this shot was a conscious attempt to hit up more.

So, there are definitely some things to point out here.

First off, the Launch and Spin Axis of the golf ball do not match perfectly with the D-Plane model (They rarely do, actually, as almost all golf shots experience some amounts of gear effect).  The Expected Spin Axis (assuming centre contact) created by this shot's D-Plane components would have been ~11.5°, instead of the Actual Spin Axis at 5.5°  This suggests that the shot was hit slightly towards the toe (causing the spin axis to tilt more left).  If I'd hit the sweet spot, maybe this shot would have faded all the way back to target...

We also see the Horizontal Launch of the ball as being further right than the Expected Horizontal Launch, which can again be explained by the toe hit (Check out this blog on off-centre contact for related information: The Effects of Miss Hits).

We see a very similar effect in the Face-On view; the Vertical Launch of the ball is actually higher than the Dynamic Loft.  This suggests that the contact was high on the face, which will also normally lower the Spin Rate.  While I'm not sure exactly what Spin Rate should be expected from these specs, I do know that my average Spin Rate is depressingly higher than this shot was.

Now, since this shot has a fairly low Spin Loft, we would expect the initial Launch of the ball to more closely match the club's Face at impact, but have actually launched outside of the D-Plane due to the off-centre contact.  Combining the D-Plane's with knowledge of the effects of off-centre contact can fully explain ANY golf shot.

Feel free to contact me with any questions regarding this, or any other, post.  Thanks for reading!

- Mark

For more information and better explanations on related topics, check out The Complete D-Plane, an educational video by John Graham (JohnGrahamGolf.com & @JohnGrahamGolf) and myself due to be released on April 3rd, 2012.  Follow myself (@StrongerGolf) or John for full details on the release.