Posted by: Jack Mankin (MrBatspeed@aol.com) on Sun Jun 13 12:35:08 2010

Hi Joe

I think we can conclude from Chris's site that he does not believe torque applied at the handle through the forearms and hands can cause the bat to rotate (bat-head to accelerate). First, we need a clear definition of torque. Below are two definitions I got from Google.

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Torque, also called moment or moment of force (see the terminology below), is the tendency of a force to rotate an object about an axis,[1] fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist.

Torque is the product of two forces being applied to an object from opposing directions that cause the object to rotate about a point.
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Since Chris rejects torque as a factor in accelerating the bat-head, he obviously rejects PLT, THT and BHT.

Let us first address PLT. Chris states on his site, -- "The concept of Whip states that the flying out of the bat into the strike zone is driven by conservation of momentum, and the sequenced acceleration and deceleration of the parts of the body, rather than by the active torqueing of the hands and/or the wrists."

I am placing below a video that shows the bat-head accelerating rearward 'before' the body rotates. Therefore, there is no "Whip" or "conservation of momentum, and the sequenced acceleration and deceleration of the parts of the body" involved in this phase of the swing. The bat-head is being accelerated from torque (PLT) applied at the handle -- top-forearm and hand being pulled rearward at a faster rate than the bottom-hand.

PLT to THT

Now, let us address THT. -- THT is different from PLT in that the THT phase starts once shoulder rotation is initiated and lead-shoulder is pulling on the bottom-hand. As the video below shows, THT applies torque at the handle in two forms. (1) Hands applying force from opposing directions. (2) The rotation (or twisting) of the back-forearm. -- Do these actions not fit the definitions of "Torque" above?

Rather than accepting my word, test it for yourself. (1) Bring the bat to your launch position and while pulling your bottom-hand forward, pull rearward with your top-hand. Did the bat-head not accelerate rearward? (2) Take your bottom-hand off the bat and rotate (or twist) your back-forearm. Did that "torquing" (Chris's word) action accelerate the bat-head? -- Then apply both actions (1 & 2) at the same time. -- That is THT

THT Mechanics

Now, let us address BHT. "Torque is the product of two forces being applied to an object from opposing directions that cause the object to rotate about a point." -- To illustrate BHT, think of the bat handle as a "four-prong-tire wrench" and you are attempting to rotate a nut. Pushing both hands in the same direction would not turn the nut. Neither will this action accelerate the bat-head in the baseball or softball swing. We must apply forces at the handle from "opposing" directions.

Since the top-hand is being driven forward from the rotation of the body, the bottom-forearm and hand should be applying a rearward force to maximize torque and accelerate the bat-head to contact. Below is a video of two high level swings exhibiting BHT. Note the rearward pull of their lead-elbows and forearms. -- That is BHT

Burrell & Bonds -- BHT

Jack Mankin