The terminal swing center

[Virtuoso]

Just spit-balling here. Let's take a look at the arc of the clubhead cg from approx 1 foot before impact and trace it to 1 foot after impact. Let's then find the instantaneous center of that arc. This is your terminal or "eventual" and actual impact swing center.

All kinds of crazy things happening in the entire swing, plane shifts, lateral and rotational movements, levers unfolding, etc.

When "centered" swing teachers/theorists are trying to get the student to stay on the swing center, what swing center are they talking about? I know some say sternum, some maybe say the left shoulder on backswing and right shoulder on follow through should occupy the same space, and some use other descriptors maybe? How do those types of definitions of swing center really relate to what I've described as a "terminal swing center"? Are they related in any way?

If those types of teachers are right, what if their student missed the "sternum swing center" by 1 inch or 6 milimeters, or 4 thousands/inch? And how could they tell the deviation? And what are the cascading consequences of missing by small increments?

And, if they are wrong, and their swing center definition is arbitrary, can they run the risk of having to actually have their students "moving backwards" to find the terminal swing center? If so, "backing into", or having to "expand into" the terminal center must have big consequences for the cascade of swing events.

I just don't know about the wisdom of arbitrary (and static address) swing center asignments. Thoughts anyone?

Something to think about: when you mention the analogy of the baseball batter loading away and stepping forward, people jump up in arms and say, "Wait a second! The batter is reacting to moving ball! That's different!" Fine, the kid is playing tee-ball. He wants to hit it over the center field fence....does he now stack and tilt at it?

 

[spktho]

Something to think about: when you mention the analogy of the baseball batter loading away and stepping forward, people jump up in arms and say, "Wait a second! The batter is reacting to moving ball! That's different!" Fine, the kid is playing tee-ball. He wants to hit it over the center field fence....does he now stack and tilt at it?

There is actually more lateral movement when kids hit off a tee in baseball. That's where a lot of their "power" comes from. With a pitched ball, less movement is usually better and less "power" from the hitter is needed.

I tried my interpretation of that method for about 15 minutes. I pretty much immediately knew their premise is wrong for me.

 

[JonWil]

My spit-ball would be that if the clubhead is a free body in that zone then the swing center would be insignificant. Of course, if the swing center is an 'absolute', existing independent of where we think it is in our swing design, then I am out of my depth and I'll take my bat and glove and go home.

 

[Cloran]

I think it doesn't matter so much where the swing center is at impact vs setup, just so long as the golfer can get to their desired impact position from their setup position consistently.

If a centerred pivot model works best for that golfer, fine by me. I don't see any harm in it.

What are the cascading events that occur when the golfer that moves their center (pick one) rearward to BM4 (sorry, I'm so comfortable with the "P" thing... "BM" works, right?) and misses their impact center by 4 microns... 1"... ?

I think it would be the same for both methods. If you can't get into good impact alignments for the desired shot then you're gonna struggle with your consistency.

 

[Virtuoso]

I think it doesn't matter so much where the swing center is at impact vs setup, just so long as the golfer can get to their desired impact position from their setup position consistently.

If a centerred pivot model works best for that golfer, fine by me. I don't see any harm in it.

What are the cascading events that occur when the golfer that moves their center (pick one) rearward to BM4 (sorry, I'm so comfortable with the "P" thing... "BM" works, right?) and misses their impact center by 4 microns... 1"... ?

I think it would be the same for both methods. If you can't get into good impact alignments for the desired shot then you're gonna struggle with your consistency.

Good response Cloran, I absolutely agree that nothing matters if you've found a way to get to your impact condition consistently.

I think I'm suggesting that you really can't make a rigid instananeous relationship with the eventual impact center and the backswing pivot and arm swing.

.....and if you do, you'll have a hard time getting a good wind up in the backswing....that allows you to use all the parts of your body to deliver the clubhead straight into the back of the ball, with the right amount of dynamic loft for that particular club.

Cloran, in other words, you shouldn't even be trying to find or stay on a pivot "center" in the wind up.

Now, having said that, there may be some sense of trying to find the eventual impact center on the downswing: the feel would be shift to, turn through and explode out from that place. AND, I think that "place" is located primarily by where you feel the pressure under you feet. But, the downswing does not begin at your feet, it begins at the cg of your body--the pelvis. It's just that you can feel where the cg of your body is by monitoring your foot pressure.

With this type of thinking, you are initially moving slightly targetward with your pelvis to find the eventual impact center.

In "centered pivot" swings, you run the risk of having to move up and backwards to find the eventual impact center, and this in conjunction with a club that is approaching from too far inside...with entirely too much forward shaft lean with the longer clubs (as an example, golfers doing S&T even slightly wrong are horrendously bad with driver and long irons).

...not to mention, centered pivots use mostly just the friction under their targetward foot, and they push up and down instead of twist; that is just not a good way to develop angular velocity.

 

[bryan@nobackswing.com]

i find it hard to believe that a centered "S&T" type swing doesn't sacrifice some distance. but one argument for the centered swing is that it helps golfers make ball-first contact. and improvement there could conceivably allow people to hit it further even with less clubhead speed.

Something to think about: when you mention the analogy of the baseball batter loading away and stepping forward, people jump up in arms and say, "Wait a second! The batter is reacting to moving ball! That's different!" Fine, the kid is playing tee-ball. He wants to hit it over the center field fence....does he now stack and tilt at it?

i love watching tee-ballers. batting in tee-ball is the closest analogy to driving a golf ball i can think of, especially with the way i swing.

 

[Brian Manzella]

Steven Nesbit has done a lot of work on this subject....I'm very busy, but maybe Mike Jacobs or Mike Finney could chime in.