Batted Ball Distance

[FiveFrameSwing]

JJs, I take it that you haven't used a Zepp.

nope. Are you saying it is lock down accurate and can be trusted? That would be awesome, but I had tried to find some sort of technical specs on it a while back, a comparison to say high speed cameras to verify it's accuracy and i couldn't find squat. I could find a lt of celebrity endorsements though so that should sell me. If you have some testing data that proves it as a product please share it.

Like any instrument, even a radar gun, the values being reported have a degree of error associated with them.

One thing I believe I learned from using the Zepp is that a focus on hand path beats a focus on bat speed.

 

[JJsqueeze]

so is there any accuracy info you can share? I couldn't even find their stated specs, much less any testing data showing it compares to other measurement techniques.

 

[FiveFrameSwing]

nope. Are you saying it is lock down accurate and can be trusted? That would be awesome, but I had tried to find some sort of technical specs on it a while back, a comparison to say high speed cameras to verify it's accuracy and i couldn't find squat. I could find a lt of celebrity endorsements though so that should sell me. If you have some testing data that proves it as a product please share it.

JJs, you initially asked about how bat speed was measured at impact.

The Zepp is one such instrument for measuring bat speed at impact.

You then stated that the Zepp measured the movement of the knob and recommended thinking about that.

The Zepp sensor is a gyroscope and accelerometer, which allows it to determine orientation and speed.

Now the concern is about accuracy.

The original post is speaking of two swings with a 8mph speed differential at impact. IMO the Zepp is capable of differentiating barrel speed to within this range.

The reason I suggest that you haven’t worked with it is because I’ve found, that my assessment of whether a swing was slower or faster, was generally confirmed with the Zepp. That is, rather than the stray misreading, the feedback from the Zepp appeared relatively accurate … and I make this claim having used the instrument with several hitters.

I don’t have the accuracy specifications on the Zepp. Wish you success in finding that information.

That said, my original answer remains … the Zepp measures bat speed at contact.

 

[Stever]

I have used the Zepp, Atec, and even the Louisville Slugger radar. The numbers I originally posted are pretty accurate based on all the devices. There is without a doubt a gap in their batspeeds.

I believe that 625ender hit upon the right idea IMO. I believe its the batspeed sustained right after contact, and Demarini talked a lot about this, that is showing the difference in batted ball distance. Mankin, I believe, suggested that all energy and speed should be about depleted at contact and follow through is a by product of the slowing process. I started this thread for thoughts, as I believe the bat speed needs to be sustained as much as possible through a wider range of motion......so.... we do not suffer a big let down in bat speed when bat and ball collide.

I believe the slower bat speed girl has stronger hands/forearms/back/triceps/etc. and maintains a greater bat speed through the ball. I believe Mankin used an analogy of throwing an axe head at a tree, I believe the axe should chop down the tree with one swing or aim to sustain the bat speed past the front foot, not just to impact.

I am talking about two sophomores that are D1 verballed, they do have decent swings (both).

 

[FiveFrameSwing]

I have used the Zepp, Atec, and even the Louisville Slugger radar. The numbers I originally posted are pretty accurate based on all the devices. There is without a doubt a gap in their batspeeds.

I believe that 625ender hit upon the right idea IMO. I believe its the batspeed sustained right after contact, and Demarini talked a lot about this, that is showing the difference in batted ball distance. Mankin, I believe, suggested that all energy and speed should be about depleted at contact and follow through is a by product of the slowing process. I started this thread for thoughts, as I believe the bat speed needs to be sustained as much as possible through a wider range of motion......so.... we do not suffer a big let down in bat speed when bat and ball collide.

I believe the slower bat speed girl has stronger hands/forearms/back/triceps/etc. and maintains a greater bat speed through the ball. I believe Mankin used an analogy of throwing an axe head at a tree, I believe the axe should chop down the tree with one swing or aim to sustain the bat speed past the front foot, not just to impact.

I am talking about two sophomores that are D1 verballed, they do have decent swings (both).

Here is what Ray DeMarini claimed.

o Player-A: 95mph pre-contact and 89mph post-contact.
o Player-B: 95mph pre-contact and 56mph post-contact.

Ray was assuming a squared (head on) collision. He concluded from his "data" that this is the reason that Player-A drove the ball farther.

The good doctor explained that Player-B hits the ball farther.

Ray was a salesman and businessman. Ray had a business reason to increase the sale of light bats ... and perhaps he fabricated data and made up stories.

If you have a Zepp then you know that barrel speed drops off steeply after impact (actually, the sudden drop off in barrel speed begins just prior to impact, which the Zepp correctly records).

 

[Stever]

How on earth do you have the ability to measure bat velocity at impact? The numbers don't add up. All things being equal, the only thing to explain the difference as you describe it would be that one didn't square up the ball on the sweet spot as well as the other, or hit into a wind...or used a different ball. rethink the measurements. This is not about follow through-what happens after contact is useless, the bat could stop dead and the ball would go just as far. The bat/ball collision is so fast that the hand no longer impart speed to the ball after the instant of contact. By the time the oscillation from the impact has traveled to the hands and then back, the ball is gone.

This is where my opinion differs. I believe if the bat head, if it could, would stop at impact, you wouldn't get half the distance. You must go through the ball, maintaining as much of that 71mph as you can. When the bat and ball collide your bat speed significantly slows down. Those who maintain a greater bat speed through the ball will hit it further, IMO

 

[FiveFrameSwing]

This is where my opinion differs. I believe if the bat head, if it could, would stop at impact, you wouldn't get half the distance. You must go through the ball, maintaining as much of that 71mph as you can. When the bat and ball collide your bat speed significantly slows down. Those who maintain a greater bat speed through the ball will hit it further, IMO

Yes, you want to go through the ball ... that is a measure of energy transfer efficiency.

Yes, you want to go into impact with a high speed ... and yes, you want the barrel to be in the process of being thrown to extension.

No, to maintaining speed post impact. It is the whipping action that causes the peak in barrel speed just prior to impact. To maintain that speed post impact, which any Zepp reading clearly indicates isn't happening, would be to retard the whip.

 

[FiveFrameSwing]

Below is the Zepp result from one of Ortiz's swings.

Note the rapid drop off in barrel speed beginning just prior to impact.

He is not maintaining bat speed post impact.

The steepest change in barrel speed takes place in terms deceleration post impact.

Understanding 'whip' and 'release' is important. Understanding that it is about the creation and release of energy going into impact ... and not about re-exerting an effort post, or at, impact.

 

[Greenmonsters]

I have used the Zepp, Atec, and even the Louisville Slugger radar. The numbers I originally posted are pretty accurate based on all the devices. There is without a doubt a gap in their batspeeds.

I believe that 625ender hit upon the right idea IMO. I believe its the batspeed sustained right after contact, and Demarini talked a lot about this, that is showing the difference in batted ball distance. Mankin, I believe, suggested that all energy and speed should be about depleted at contact and follow through is a by product of the slowing process. I started this thread for thoughts, as I believe the bat speed needs to be sustained as much as possible through a wider range of motion......so.... we do not suffer a big let down in bat speed when bat and ball collide.

I believe the slower bat speed girl has stronger hands/forearms/back/triceps/etc. and maintains a greater bat speed through the ball. I believe Mankin used an analogy of throwing an axe head at a tree, I believe the axe should chop down the tree with one swing or aim to sustain the bat speed past the front foot, not just to impact.

I am talking about two sophomores that are D1 verballed, they do have decent swings (both).

I think there's a physics problem with your conclusion. For the pre-contact velocities, think about two cars instead of bats - it takes an extended period of time to slow and eventually stop after you lock the brakes so the faster car will still be traveling faster or nearly as fast milliseconds later. So unless your one hitter is intentionally starting deceleration well prior to contact, something else is causing the difference IMO.


I'm trying to find and go back through some older threads that may be enlightening. This one http://www.discussfastpitch.com/softball-hitting-practical/18090-hand-action-contact-7.html involved pobguy (PhD physicist/baseball geek), Frazier's "no hands" homerun etc. and maybe the D1 college team using the abbreviated follow through.

 

[FiveFrameSwing]

GM, there's more than just a physics problem here.

What I don't get is how Stever can own a Zepp, claim it is accurate, and reach the conclusions that he has reached.