Posted by: tom.guerry (tom.guerry@kp.org) on Sun Mar 31 09:05:00 2002

>>> what Nyman describes as (after flail) the whip portion/dog hitting end of leash as "L" comes out of back elbow and front forearm extends at elbow fully decelerating torso. <<<
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> Hi Tom
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> Once again, I have grave reservations referring to a “whip” action as source for generating bat speed. Naturally, I agree that the body’s rotational energy transferred via a circular-hand-path (flail, if you prefer) is responsible for a good portion of bat speed generation. But, it is inaccurate to attribute the balance of that bat speed to a whipping action such as Nyman's, “dog hitting end of leash.”

Acceleration from a whip action depends on energy stored in a moving mass (whip, dog or bat) and the end (tip, butt, or bat-head) accelerates as the uncoiling mass decreases. Many batters have been mislead into thinking that if they just accelerate the bat knob first, the energy stored in the bat or system will cause the bat-head to come “whipping” through as the hands near full extension. Well, it won’t, and that is what I proved with the test (steering wheel knob on bat) in the video. Without the ability to apply torque, the bat-head never accelerated as the knob slowed to a stop – “that dog never came around.”

It is not a whip action or the release of stored energy in the bat (or dog) that accounts for the balance of bat speed generation; it is the constant application of “torque” that adds to the chp transfer. For more linear hitters who accelerate the bat knob first, torque is mainly applied as the back-hand is driven passed the lead-hand (push-pull action) as the hands near full extension. --- So once again, it is “torque” not “stored energy in the bat or whip action” that brings the bat-head around. Bat speed depends on the rate of angular displacement on the hands and the amount of torque applied from initiation to contact.
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> Jack Mankin
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>

Happy Easter Jack-

I should have remembered how much you dislike the term whip because of the inaccuracy of the word(mass not tapering,for example).I have the same distaste for "throwing the hands" but that doesn't bother other people as much.

I do think it is usefulanalytically to segment the swing into the equivalent of "flail" and "whip" the way Nyman does.I am still not sure how one phase exactly transitions into another,I am particularly interested in the back foot motion you see with each phase,which I believe is a marker of reactive torque.

In an efficient/desirable swing,the back toe drags(unless obscured by weight bearing due to backward leaning axis)during the flail portion of the swing,indicating that the hips have decelerated and transferred momentum upward.Until this has started,the bathead should stay in/not demand significant transfer of energy from torso.Once toe drag is underway,the bathead comes out.This process of energizing the torso by hip/lower body deceleration and transfer of momentum has been referred to by me and others at setpro as "rotational whip" because there is sequential transfer of momentum and tapering of mass from the lower to the upper body.Of course there are muscle contractions creating force and leverage(change of direction)and elastic forces too.

Next,if you watch the back foot you will see the ankle turn behind the player.I think of this as a second wave of reactive torque as the "L" comes out of the back elbow and the flex comes out of the front elbow.This more rapidly sucks energy out of the torso(which turns less on the outside location) and is I believe what you(Jack) might call a tht phenomenon,since the idea is that the bottom hand is relatively stationary and the top hand is moving around this bottom hand oarlock(the opposite being the case with bht on the inside pitch).In the past I have thought of tht more at/before initiation than what might be happening at contact.In any case,connection needs to be maintained through contact.For the outside location this means the upper front arm should not get away from the torso while any flex comes out of the front elbow.

Just looking at the back foot can tell you a lot about the swing.The arm swinger has no toe drag because there is no store and transfer sequence for the lower body to develop and transfer momentum to the torso(lower body energy doesn't get transformed into batspeed).All they get is the ankle turn,then the back foot comes around with followthrough.The worst swings just bring the back foot around.

You can see the desired action on the delgado clip setpro thread 000571.

Do you find these phases useful at all? Is there a significantly different principle at work?

What would you call the phases?

Are the transfer mechanics best described as just variations of how torque demands transfer out of the torso as oppose to "whip" ? Is the torso just like an energized flywheel with transfer only triggered by the chp and how the center of mass of the bat is torqued out?

Thanks for wading through this!