Slices & Hooks - Trackman Style

[cwdlaw223]

How much disparity between the face and path is needed on a driver for a slice? a hook?

4*? 5*?

I know that if the face is square and the path is in to out by 3* with a driver the bill will draw very hard.

Just curious.

 

[natep]

I read somewhere that the path needs to be 2.5x the face to hit a curved shot to the target.

So if you impact the ball with a 2 degree open face, you need a path of 5 degrees inside out to hit a draw to your target.

 

[cwdlaw223]

I'm looking for the disparity that will cause a huge slice or duck hook (instead of a nice draw or fade). Just curious how much of a disparity for each will cause such a wild miss.

 

[savydan]

It depends on the loft - specifically the Dynamic Loft - which defines the top of the D-plane so to speak.

For a driver, you need less difference between the face and the path in the horizontal direction to make the ball curve more because the lower DL will put the D-plane on more of a slant.

Like a ladder leaning against a house - will a 5 foot gap between the base of the ladder and the base of the house result in a large lean in the ladder? Depends on how tall the ladder is (analogous to the DL).

That path 2.5 times the face is a totally bogus old wive's tale/rule of thumb that makes no mathematical sense.

If you have a face 10* left, the path needs to be 25* left??? A 15* horizontal gap in face/path? Won't get airborne. Careful about rules of thumb with D-plane/Trackman.

 

[softconsult]

Don't forget gear effect. If you hit it in the heel side of the Driver face it will impart
fade spin and vice versa for toe hit.

 

[Jared Willerson]

Savydan and others have a formula for aim...and I thought there was one floating around for face/path relationship depending on the HSP somewhere.

 

[savydan]

Brian had that Swing Direction Calculator about 2 monts ago? I posted the basic trig formula several times.

But those are more resultant path deals - not calculating curvature/D-plant slant.

A really motivated high school trig whiz could come up with a formula knowing:

True Path
Club Face
and Dynamic Loft

Then get the tilt of the D-plane....

Then use Tuxen's rule of thumb: 0.7% curvature for every 1* axis tilt.

Something for a rainy day...........

 

[Kevin Shields]

Dont forget about club speed influencing amount of curve.

 

[savydan]

Good point, Kevin.

If Jamie Sadlowski zeroed out a 9 iron and produced 18,000 rpm of "pure backspin" instead of the usual 9,000 rpm, the ball still wouldn't curve left or right because his d-plane would not be tilted.

If he did tilt his d-plane, would the increased spin cause more curvature?

Tuxen's 0.7% curvature per 1* axis tilt rule certainly implies that spin rate does not play any role (or perhaps significant role) in the amount of curvature.

Is Fast Freddie's rule of thumb semi-legit? Or is it just another rule of thumb that has so many buried assumptions that it's next to useless?

 

[Kevin Shields]

I take it you dont trust Tuxen? Hmm?

 

[savydan]

Not him personally or his machine...but his rules of thumb.

Like the Angle of Attack does not change spin rate. Or as stated in his last newsletter, hitting down on the ball does not increase spin.

He is making a HUGE assumption that the change in angle of attack is also producing the same change in Dynamic Loft. But, IMO, he is not being clear with the reader that this is his assumption. And he presents these "rules" right in the middle of his otherwise nice explanations thereby leaving the reader confused since it's natural to remember the simplest statement and forget the vague assumption(s).

 

[cwdlaw223]

I suspect someone out there has seen a hook/slice pattern between the disparity regarding the club path and face angle.

I already know that the D plane tilts more with lower dynamic loft/speed. I'm looking for general disparities between path and face angle that will cause a shot with a driver to be a slice or duck hook.

Assume the average PGA tour numbers for club head speed and pick a dynamic loft within reason for a driver.

 

[Kevin Shields]

Tough question. Even though 1/2 the path with the face will curve it to the hole, the bigger the disparity the bigger the curve. With a level attack and, say, 12 degrees of dynamic loft, I would say 5 or 6 degrees difference in the face and that thing is starting to curve alot.

 

[cwdlaw223]

Kevin -

Thanks. That's what I thought. Next time I'm on a Trackman I'm going to hit some slices and hooks just to "feel" the numbers.

 

[mgranato]

What do you consider a hook? Slice?

I'm always interested in how folks make the distinction between "pretty straight", "tiny draw", "baby fade", "soft hook", "power cut", etc.

I've stood in the "face on position" on the tee and felt like I was going to be hit in the BACK of the head by this guy's slice - only to hear him complain about how he "over CUT that one". His slice was almost a draw.

 

[mjstrong]

It depends on the loft - specifically the Dynamic Loft - which defines the top of the D-plane so to speak.

I'm just being a little nit-picky here, but Dynamic Loft is only a component of what actually "stretches" out the D-Plane. Spin Loft is actually the variable you're looking for, which takes into account both Angle of Attack and Dynamic Loft. This is why hitting up on drivers, even with a high launch angle, can still be easy to tilt the spin axis.

 

[cwdlaw223]

What do you consider a hook? Slice?

I'm always interested in how folks make the distinction between "pretty straight", "tiny draw", "baby fade", "soft hook", "power cut", etc.

I've stood in the "face on position" on the tee and felt like I was going to be hit in the BACK of the head by this guy's slice - only to hear him complain about how he "over CUT that one". His slice was almost a draw.

Hook/Slice = In the trees! They're both golf porn (you know it when you see it)!!!!!

 

[Kevin Shields]

Not him personally or his machine...but his rules of thumb.

Like the Angle of Attack does not change spin rate. Or as stated in his last newsletter, hitting down on the ball does not increase spin.

He is making a HUGE assumption that the change in angle of attack is also producing the same change in Dynamic Loft. But, IMO, he is not being clear with the reader that this is his assumption. And he presents these "rules" right in the middle of his otherwise nice explanations thereby leaving the reader confused since it's natural to remember the simplest statement and forget the vague assumption(s).

I cant speak for what confuses people but I feel he made it very clear that attack angle doesnt increase spin unless spin loft is increased. Im not sure what was assumed or not made clear. It is most definately spelled out.

 

[mjstrong]

Dont forget about club speed influencing amount of curve.

Can you elaborate Kevin? Are you saying that more clubhead speed would change a shot's spin axis, all else being equal? Or are you simply referring to more clubhead speed /ball speed results in a longer flight, giving the ball a chance to spin more given the same spin axis?

Thanks.

 

[Frans@France]

Like I said in the "wind effecting..." thread
For those of you who would like to do these kind of calculations try
- trajectoware (free)
- OptimalFlight (paid)