## Monday, April 12, 2010

### More Trackman Screen Views

I saw this video of Trackman showing some screen views of a driver going thru impact and I thought this could further help some readers understand Trackman:

Let's take a look at some of the numbers and then what the animation is trying to show us.

Attack Angle - +3.6*
Dynamic Loft Angle - 16.6*
Vertical Launch Angle - 15.3*

This shows the golfer with an upward attack angle. The dynamic loft is the loft of the club at impact. The vertical launch angle is angle that the ball launches initially. Because this golfer has a very upward attack angle with the driver, the dynamic loft and vertical launch angle increases. I believe they prescribe something in the 10-14* range for vertical launch angle. So this golfer may want a lower lofted driver. The animation on the upper left corner of the screen shows what an upward attack angle of 3.6* looks like.

Now let's take a look at the bottom left corner of the screen.

Club Path - +3.6*
Face Angle - +1.6*
Horizontal Launch Angle - +1.8

Remember, positive numbers mean the ball or the clubhead is going rightward and negative numbers mean leftward.

Now, let's remember some things.

This golfer has a +3.6* attack angle. In order to hit it DEAD STRAIGHT AT THE TARGET, this golfer pretty much needs to have a horizontal swing plane of about +3.6* as well.

However, this screen does not show what the horizontal swing plane is for this shot.

It shows a club path of +3.6*, but that's not the same thing as the horizontal swing plane.

If the horizontal swing plane was +3.6*, the club path would be near 0.0*.

Instead the club path winds up being +3.6*, so we can conclude that the horizontal swing plane is quite a bit out to the right.

NOW, look at the animation in the upper right hand corner. As you will see, they show the club swinging along an imaginary incline plane board. If you look at it, you can see that the incline plane board (which is really the horizontal swing plane) is out to the right of the target.

Still, that doesn't mean that it was a 'bad' shot. What we know from 'the new ball flight laws', the face is out to the right, but the path is further out to the right than the face at impact. This should result in a push draw back at the target. And if the golfer made good contact, they will likely have optimized their distance off the tee with that upward attack angle.

Ball Spin - 1,985
Spin Axis - (-3.4)

Ball spin is just the backspin rate of the driver. At 1,985 rpm's, that's an excellent low spinning driver shot. This ball will roll forever.

Now remember, this golfer had a 'horizontal angle' of +1.8*. We stated that with looking at his clubface angle and clubhead path he should hit a push draw.

The horizontal angle means that the ball started to the RIGHT of the target by 1.8*. The spin axis is -3.4*. Meaning that it had hook spin of 3.4* (a positive number would have slice spin). So it does appear that this golfer hit a push draw. And as you play the video, you will see the animation show the ball starting out to the right with hook spin.

3JACK