I came across a YouTube short of Xander Schauffele’s driver swing, which is pretty good as it really only has one flaw – but that flaw leads to another flaw, and then a required compensation to avoid injury.
While listening to the USGA narrator, I heard yet another Modern Golf Swing myth that I have been hearing and seeing for years, so let’s take a look at it, shall we?
First, the swing itself:
As I said, a pretty good swing, very powerful – but it’s a Modern Golf Swing action, meaning Xander is keeping his leading heel firmly planted on the back swing pivot, and that brings us to the USGA’s myth.
“The wider the arc, the faster the outside of that circle will move,” the narrator says, referring to the wide back swing arc Xander is creating by keeping his trailing or right arm straight instead of folding at the elbow:
So the myth is that a wide arc on the takeaway pivot will create a wider arc on the down swing, and the outside of the arc would be the club head, which would move faster.
There’s only one problem – the wide arc is on the back pivot, and the down swing arc will be the exact same width as with a normal back pivot because the arc is created by the leading arm from the shoulder down to the club head at the end of the shaft.
Unless you can lengthen your arm or club shaft coming down, you will always have the same arc width, whatever you do on the back pivot.
The actual positive function of the straighter trailing arm on the back pivot is that it fosters an early shoulder turn and perhaps makes for a greater shoulder turn before the trailing arm does fold getting to the top, but that has nothing to do with a wider arc coming down.
You simply possibly created a greater shoulder turn which adds more power to the down swing. Period.
Now, for the swing flaw of the planted heel – Xander compensates by turning his leading foot nearly square instead of having it flared, and that’s because the planted heel restricts hip turn.
Now he’s added another flaw to the planted heel – a too-squared leading foot at address.
So, to get more hip turn avoid placing undue strain on his leading ankle, knee and hip (try pivoting with a flared and squared leading foot with your heel planted and see the difference in strain and hip turn), he squares that leading foot.
The problem now becomes the squared leading foot, and with the big hip turn through impact to the finish, Xander has to twist his leading foot into an unnatural and dangerous position to avoid wrecking his leading leg joints from ankle to hip, which will cause inconsistency.
That’s likely why he’s 158th this season in driving accuracy off the tee (54.17%), but if he only freed up the leading heel to lift naturally to enable a full hip turn, he be able to have that leading foot flared out the way it should be, and he wouldn’t have to roll his ankle over through impact.
He’d not only gain more consistency, he’d also get more power and distance out of his already powerful swing.
But today’s players will do anything to improve their speed and power except what they should be doing – swinging with a free hip turn and a leading heel that comes up to allow it.
By randomly insisting on that one silly thing (keeping the leading heel nailed down), they are having to invent all sorts of compensations during the address and swing phase just to swing that way.
It makes no sense to me, but I’m just a swing analyst and researcher.
WAX Golf 
Your analysis reads like an accident report where all reactions are in response to the initial wrong action.
That is hilarious, Chief – because every time I analyze these swings, I’m watching a slow-motion train wreck. And yes, it all starts from the faulty setup to accommodate the planted heel hip-restriction!
So how much would a flared leading foot alleviate the sin?
Dunaway played with square feet but he didn’t force his leading heal down.
Still though, it seems to me the front foot wants to flare out at the end of the swing as seen in the modern swing malady of “the flying foot syndrome” so why not start with it flared.
Of course, there is the other myth of torque the spine to the breaking point basis of the modern swing that needs to be dispelled which is why the leading heal is kept planted.
The natural progression of mechanically correct swing movement is grasped easier with a flared foot as the lifting heal fits like a piece of a puzzle into the sequence.
A couple of things here, Chief – for one, Dunaway did have a very squared foot position but, because he had a narrower stance, he would simply shift to the leading foot and turn into that leading hip. In this regard, the flared foot was not necessary.
Second, these Flying Foot swingers are not shifting into the leading foot and turning into the leading hip. They are turning violently in place like corkscrews, which would require a flared leading foot to alleviate the twisting forces – but since they are turning in place, there would always be a Flying Foot unless they release the trailing foot and turn into the leading hip.
It’s a horrible way to swing and no one who actually teaches this garbage deserves a penny in payment- rather, they should be sued for damages by injured students or banished altogether for not knowing anything about kinesiology.