Calculating Face @ Impact with Club Path

[TomHicks]

Hey!

I have a GC3 (which doesnt have club face data) and I want to know if there's a way to calculate club face at impact with only using:

1) The club path
2) Shot shape

As I understand it, there's two key factors that determine ball flight:

1) Face at impact
2) Club path

I suspect strike location may affect it, particularly if its a hozzle strike - but ultimately I believe its those two.

Now, if you know that for example on average my path is "In-to-out" by, lets say 2-3 degrees and the ball moves either, left, straight or right - could you in theory know the club face at impact?

Could someone please try to explain if its possible and how I can simply work it out?

[OttawaP]

If it draws nicely back to centerline then its around 1/4 to 1/2 closed to path. Is it flies straight right, then path = club face. (for righties) if it hooks then the face is way closed, if it starts right and goes righter then the face is open to path.
I'd love to have the actual numbers but those points are typically good enough.

[Stetson]

You can’t get a precise calculation. You are better off just thinking about it in terms of “in relation to the path”. Gear effect based upon impact location will make a large difference that makes it tough to know.

[Khilgen4]

In addition to seeing what it does in the software, you can also look at the side spin / spin axis data and get a sense just from the device to what degree you were open or closed to path. The more side spin you are more drastically open or closed to the path. The smaller amount of side spin, the closer you are to the actual path. (Generally speaking). But that amount and direction of spin will also show up in the sim software by looking at the ball flight. The numbers would simply let you know some more data. I'm about to pull the trigger on a GC3 as well and have been wrestling with whether Impact and Face to Path data is really worth nearly $10k between the GC3 and GCQuad. For me, I don't think it is considering I'll have path, side spin and software view.

[TomHicks]

So part of the reason I'm asking this is my golf coach has asked me to swing more in to out to stop coming over the top of the ball.

Which, ask you can see from the 10 1/2 swing practice shots below, I'm somewhere achieving. That said, all shots are going left, now I'm trying to work out based on the Carry & how much offline the ball is, is it going left because I'm in-to-out or is it going left because the club face is a little closed?

My guess is its a bit of both?

[preludesam]

That said, all shots are going left, now I'm trying to work out based on the Carry & how much offline the ball is, is it going left because I'm in-to-out or is it going left because the club face is a little closed?

Face angle is 70-80% of where the ball is going. You are right to assume the club face is closed to the path and in your case even closed to the target. You should be trying to get an in-out path with a R Side Angle (Horizontal Launch Angle) and a Tilt Angle (Spin Axis Tilt) closer to zero. Double digits with Tilt Angle results will give you a hook or a slice instead of a draw or a fade. Notice how your Side Angle left or right almost always matches the Offline measurement.

It's really good that you are closing the face though. I would just keep working with what your instructor asks for and not worry too much about the other aspects. Instructors have a plan on how to get you to your goals. When you can consistently control the club path and they feel you are ready then they will ask you to work on the face.

[TomHicks]

You should be trying to get an in-out path with a R Side Angle (Horizontal Launch Angle) and a Tilt Angle (Spin Axis Tilt) closer to zero. Double digits with Tilt Angle results will give you a hook or a slice instead of a draw or a fade. Notice how your Side Angle left or right almost always matches the Offline measurement.

Thanks for your feedback. Spin Axis Tilt/Tilt Angle - that is how the ball moves through the air, right? As in, a stronger number means either a slice or a hook?

What is a horizontal launch angle? How is that different from Spin axis tilt/tilt angle?

I'm a little unclear on the differences between them

[preludesam]

Spin Axis Tilt/Tilt Angle - that is how the ball moves through the air, right? As in, a stronger number means either a slice or a hook?

This is a measurement of the Tilt Angle the ball is spinning at. Think of airplane wings, both wings are providing lift but if you tilt the wings now the lift is no longer straight up causing the plane to curve. The larger the number the more the curve and as a consequence, a reduction of lift since the upward force is fractioned into side forces.

What is a horizontal launch angle?

Horizontal Launch Angle/Side Angle is a degree measurement left/right the ball started versus the target line. Zero degrees being dead straight on target and ninety left or right being a right angle to the target. To give a comparison each tic from the second hand on a clock is six degrees.

[TomHicks]

This is a measurement of the Tilt Angle the ball is spinning at. Think of airplane wings, both wings are providing lift but if you tilt the wings now the lift is no longer straight up causing the plane to curve. The larger the number the more the curve and as a consequence, a reduction of lift since the upward force is fractioned into side forces.

Horizontal Launch Angle/Side Angle is a degree measurement left/right the ball started versus the target line. Zero degrees being dead straight on target and ninety left or right being a right angle to the target. To give a comparison each tic from the second hand on a clock is six degrees.

Ah, okay - thank you! I think I got it... So if I did a "Push Straight" Or a "Pull Straight" where the club face matches the swing path from I-O or O-I then the Tilt Angle would be 0 but the Horizontal Launch Angle would be something between 0-10 for example?

[preludesam]

Yes but I would focus more on Swing Path in relation to Side Angle. Side Angle is a good rough measurement of where the face was pointing when the strike occurred. Tilt Angle is heavily influenced by strike location. This is why hitting the center of the face is important and it plays into a lot of other metrics like ball speed and spin.

[TomHicks]

Yes but I would focus more on Swing Path in relation to Side Angle. Side Angle is a good rough measurement of where the face was pointing when the strike occurred. Tilt Angle is heavily influenced by strike location. This is why hitting the center of the face is important and it plays into a lot of other metrics like ball speed and spin.

Got it, thank you! I'll keep an eye out for that.

I've been studied the 9 ball flight laws, and I'm struggling to get my head around something. As I understand in the path is In-to-Out results in one of three shot shapes: Straight Draw, Push Straight or Push Draw (depending on club face at impact).

Now, majority of my shots have a L tilt angle which you'd expect if path is in-to-out. However, some are still In-to-Out but have a small R tilt angle. Why is that?

[preludesam]

It’s most likely a heel strike. Take a look at your efficiency/smash factor on the R tilt shot. It was your fastest swing yet lowest ball speed. Premium ball speed comes from the center of the face. It’s also much lower than your other shots. Your club face was more open compared to the other shots identified by the increase in vertical launch angle and spin. Although impact location on wedges does not affect tilt as much as say a driver would, it’s still there.

[TomHicks]

It’s most likely a heel strike. Take a look at your efficiency/smash factor on the R tilt shot. It was your fastest swing yet lowest ball speed. Premium ball speed comes from the center of the face. It’s also much lower than your other shots. Your club face was more open compared to the other shots identified by the increase in vertical launch angle and spin. Although impact location on wedges does not affect tilt as much as say a driver would, it’s still there.

I see! Thank you for all your help!

[John8888]

you can estimate face angle relative to path using a GC3 but the math is complex

see

https://www.tutelman.com/golf/ballflight/3dlaunch.php



3-Dimensional Launch Conditions from Impact Conditions



Dave Tutelman -- March 6, 2007

[TomHicks]

Let me just go get a PhD in Maths and Physics first hah

[John8888]

May not be worth the 2 years to get the PHD))) .... if you hit a few balls on a GC Quad and send yourself the spread sheet you will find even the heavy math above is an "estimate". If you hit the ball perfectly in the middle of the face ...the math holds up and the calculated face angle is about right ...if you miss the centre of your club your spin numbers etc are different and the calculated face angle is not even close.