Posted by: Al_Oha (p3d0n6@hawaii.rr.com) on Mon Jan 5 23:24:40 2009

> Given the nature of the physics governing these kinetics, if each component contributes
> equally to batspeed, the result would not be a doubling, but an increase by a factor of the
> square root of 2 or a multiplier of about 1.41.....
>


I have trouble understanding this, given the apparent authority in which it is used to make a point. You assume that torque contributes to 50% into the swing, with the balance coming from CHP. Implicit in this is the assumption that kinetic formulations apply, relating force revolving around a single axis, F = MVV/r.

I submit that while the groundings in motion physics may be convincing, the validity of the premise may be open to challenge.

Consider the following:
1. Does the travel of the bathead follow a circle? A circle is an important conceptual reference to the student, but I do not think we know this factually, and with certainty. Mankin's DVD shows that the path of the wrists, and corresponding bat tip traces what the authors call a "protractor".

With due respect, I beg to differ, as our mind's eye may not be as discerning . If torque works synergistically with CHP, could it be that this force confers an influence in the perfect radius of CHP, that in final summation, an arc of sorts approaching a circle is produced? Go look at the the DVD closely and see if you agree. If so, this needs to be reconciled outside of single axis motion
kinetics.

2. In the formulation above, the contribution of torque predicts a 1.4-fold increase in the output assuming an equal force by CHP. If we apply the same to a situation with "no-torque", then that very same formula predicts an output of "0", which we know is not the case: Batspeed velocity and force can exist in the absence of hand torque (measured at 65 mph for CHP, according one author). Therefore, the formulation of F=MVV/r is overly simplistic and inconsistent, and cannot validly extropolate the measure. A workable model must be able to quantify the presence or absence of either component in the generation a force.

The point is that we do not know enough to suggest that torque indeed contributes 50% of batspeed, and at the same time provide a testable model with both physical and mathematical foundation.

That said, in the eight months or so that I have been following this website, Jack Mankin has provided the most consistent and convincing arguments on the topic. But their application has yet to be rigorously formalized in a valid model.