Brandel Chamblee going into controversy mode (Tour Player Angle of Attack Debate)

[mvmac]

 

[saevel25]

Good find there. I think Brandel needs to start using the mentality, measuring twice cut once, with his comments. Double check, then speak. 

[natureboy]

13 hours ago, krupa said:

What does Chamblee mean by a "descending blow"?

This guy says Thomas's AoA off the tee is +4.8 while the tour average is -1.3.

http://www.pgatour.com/video/2015/06/03/justin-thomas-exudes-power-and-finesse.html  (around 2:50 in the video)

How much do golfers change something like that?  I was under the impression that the answer was "never... at least, not without making a significant swing change."

Note that Brandel's quote said 'tee shots', not 'tee shots with driver' or 'driver'. Usually a fair number of tee shots with irons or woods that would likely bring the average angle of attack down for the whole round.

Bad / misleading statistics, Brandel!

13 hours ago, Golfingdad said:

So was Chamblee just referring to one particular drive where Thomas was trying to hit a stinger under the wind or something else?

Plus this on a couple of holes.

Edited January 18, 2017 by natureboy

[nevets88]

I see why McIlroy is tweeting, both of Chamblee's statements question his methods.

 

 

10 hours ago, mvmac said:

 

I think this video is also in reaction to the AoA argument as well:

 

[Pretzel]

Holy cow, Brandel is really doubling down on his crap? That's impressively dumb, to argue with the guys who hit it the longest and straightest on tour about what makes people hit the ball longer and straighter. I also don't think he understands the whole "longer drive, same accuracy" thing where a longer drive with the same accuracy travels further offline than a shorter drive with the same degree of accuracy.

[mvmac]

Grant's response to Arron Oberholser.

 

[nevets88]

McIlroy telling us how he really feels, the attached image shows he's first place in driving distance at one time last year.

 

[saevel25]

Also, a higher dynamic loft means less axis tilt on the ball. Primary reason why wedge shots don't curve and long irons do. 

So, if you hit up on the ball you can apply a higher dynamic loft with a lower spin loft. High launch - Low spin . You should actually have less potential to curve the ball if you hit up. Also, the shot will have less spin anyways. 

I found that hitting up produces a much more neutral ball flight. 

[iacas]

52 minutes ago, saevel25 said:

Also, a higher dynamic loft means less axis tilt on the ball. Primary reason why wedge shots don't curve and long irons do. 

So, if you hit up on the ball you can apply a higher dynamic loft with a lower spin loft. High launch - Low spin . You should actually have less potential to curve the ball if you hit up. Also, the shot will have less spin anyways.

That doesn't really make sense.

14° dynamic loft with -2° AoA is 16° spin loft.
16° dynamic loft with +4° AoA is 12° spin loft.

The latter is going to be easier to tilt the spin axis.

Low spin generally means it's easier to tilt the spin axis. Any "sideways" movement of the club path relative to the face has a greater effect. Consider a driver with 6° dynamic loft delivered with +5° AoA. That'd be 1° spin loft and very little spin. If that ball is hit with a face at 1° and a path at 3°… that's going to be a spin axis that's super tilted.

P.S. Grant's not exactly right about "friction" and spin and flier lies, etc.

[Pretzel]

1 hour ago, iacas said:

That doesn't really make sense.

14° dynamic loft with -2° AoA is 16° spin loft.
16° dynamic loft with +4° AoA is 12° spin loft.

The latter is going to be easier to tilt the spin axis.

Low spin generally means it's easier to tilt the spin axis. Any "sideways" movement of the club path relative to the face has a greater effect. Consider a driver with 6° dynamic loft delivered with +5° AoA. That'd be 1° spin loft and very little spin. If that ball is hit with a face at 1° and a path at 3°… that's going to be a spin axis that's super tilted.

P.S. Grant's not exactly right about "friction" and spin and flier lies, etc.

 

 

I think @saevel25 might have gotten confused on the exact mechanism, but I personally think that his primary point is true; the lower spinning shot of the two would curve less offline than the higher spinning shot (even with the difference in spin axis between the two). That said, I don't have any data to support this, though I have an idea on how to test it if data became available.

I think it would make for a very interesting experiment to have a number of good golfers hit shots off a simulator and compare the curvature of comparable shots (with very close/the same face angle and path) where the primary difference between the two is a positive versus negative angle of attack (more spin and less tilt versus less spin and more tilt). It would take a good amount of data collection since you would have to find a good number of comparable shots, but it doesn't have to be done all in one attempt. So long as you kept a log of all the important numbers (ball speed, spinrate, spin axis, angle of attack, dynamic loft, club path, and face angle are the ones that come to mind for me), it would be fairly trivial later to sort the data into different bins and subcategories based on ball speed, face angle, and club path to compare the positive versus negative angle of attack. Heck, you don't even need all the data to be from the same player if you have enough data to produce a sufficient number of comparable shots. 

 

[natureboy]

3 hours ago, Pretzel said:

Holy cow, Brandel is really doubling down on his crap?

Maybe book sales are down, lol.

[iacas]

4 minutes ago, Pretzel said:

I think @saevel25 might have gotten confused on the exact mechanism, but I personally think that his primary point is true; the lower spinning shot of the two would curve less offline than the higher spinning shot (even with the difference in spin axis between the two).

No, you can't say things like that. Which curves more: a shot with 3500 RPM spin and a spin axis of 4° or a shot with 2500 RPM spin and a spin axis of 9°?

The latter:

Spoiler

 

4 minutes ago, Pretzel said:

I think it would make for a very interesting experiment to have a number of good golfers hit shots off a simulator and compare the curvature of comparable shots (with very close/the same face angle and path) where the primary difference between the two is a positive versus negative angle of attack (more spin and less tilt versus less spin and more tilt).

You can figure that stuff out programmatically. No need to generate empirical data.

The ball is not going to react exactly the same in both directions given the angles (the "spin loft" component horizontally is often smaller than vertically), but it's awfully darn close, and you can easily sort this stuff out.

I approximated above just to prove the point that the dropping the spin while changing the spin axis only a little can result in fairly drastic changes to the resulting ball flight.

[saevel25]

1 hour ago, iacas said:

That doesn't really make sense.

14° dynamic loft with -2° AoA is 16° spin loft.
16° dynamic loft with +4° AoA is 12° spin loft.

The latter is going to be easier to tilt the spin axis.

Low spin generally means it's easier to tilt the spin axis. Any "sideways" movement of the club path relative to the face has a greater effect. Consider a driver with 6° dynamic loft delivered with +5° AoA. That'd be 1° spin loft and very little spin. If that ball is hit with a face at 1° and a path at 3°… that's going to be a spin axis that's super tilted.

P.S. Grant's not exactly right about "friction" and spin and flier lies, etc.

That makes sense. I didn't realize that lower spin loft will allow the spin axis to be tilted more easily. 

[MrDC]

Brandel admitted his mistake and apologized, so he did the right thing-

Eventually, Chamblee deleted his original tweet and apologized for the mistake. The 30 of 32 players had a negative HLA (Horizontal Launch Angle), which relates to the direction of the ball, not the angle of attack. To further understand swing analysis.

[iacas]

11 minutes ago, saevel25 said:

That makes sense. I didn't realize that lower spin loft will allow the spin axis to be tilted more easily. 

Sure you did!

3 minutes ago, MrDC said:

Eventually, Chamblee deleted his original tweet and apologized for the mistake. The 30 of 32 players had a negative HLA (Horizontal Launch Angle), which relates to the direction of the ball, not the angle of attack. To further understand swing analysis.

Yeah. A pretty stupid mistake.

I rarely understand deleting it. Just reply to yourself and say sorry. Deleting makes all the other tweets somewhat nonsensical.

[natureboy]

1 hour ago, Pretzel said:

primary point is true; the lower spinning shot of the two would curve less offline than the higher spinning shot (even with the difference in spin axis between the two).

I kind of interpreted @saevel25's point more about the tendency for higher lofted clubs to be harder to 'curve' using path / swing direction and less lofted clubs being easier to add shape with path / swing direction adjustments.

Higher loft (with same CG etc.) clubs tend to impart a more significant share of the club's energy into backspin. Altering the path (with same face angle) will still tilt the spin axis, but less noticeably relative to the primary direction the face is pointing and of lift - which is up.

Now I do think that higher lofted clubs will tend to be more prone to resulting curvature/axis tilt than lower lofted clubs from adjusting dynamic lie angle (on an uneven lie e.g.) all else (face/path) being equal.

Edited January 18, 2017 by natureboy

[Pretzel]

1 hour ago, iacas said:

No, you can't say things like that. Which curves more: a shot with 3500 RPM spin and a spin axis of 4° or a shot with 2500 RPM spin and a spin axis of 9°?

The latter

 

I stand corrected, that would be my mistake. I hadn't run any of the numbers, it was just a thought based on an incorrect assumption I had made. I still would be interested in seeing some sort of study done on it, simply because I don't know exactly how much the spin angle will change between the two scenarios (you might know, but your comment appeared to just show a general change in spin axis). That said, I don't know anywhere to readily access the data that would be needed to do a simple sanity check.

The 5-degree change in spin loft in your example seems to be a small number on the surface, but I lack the background knowledge required to judge how large of a change that truly is. I don't have the context of having worked with flightscope or trackman enough to know what the common variance of the spin axis is, so I'll just take your word for it that it is not exceedingly large in context. 

[nevets88]

Grant Waite is on a roll. Video on hitting up vs down.

 

This is what I love about the internet - someone says something that clearly doesn't correlate with the data, people chime in and make a conclusion based on real data. It's basically XKCD on steroids. In the process, we all learn more, people ask questions they otherwise would not have. We get a guy (Grant Waite) pulling off the road to make a video, an instructor videos himself doing math on a notepad and people actually watch it, @iacas makes his video above. It doesn't happen all the time, but the means is there. If only all the incorrect stuff said during golf broadcasts were dispelled. I don't mind people wanting to stir up the pot, just do it with good data. What we witnessed was a very public collective, dude, you're so wrong, and I bet the typical Golf Channel demographic is barely aware of it.