Posted by: Jack Mankin (MrBatspeed@aol.com) on Sun Feb 5 11:18:49 2006

>>> Think about the definition of creating batspeed: creating the maximum possible amount of torque on the bat handle via the hands. (I'm not saying the hands apply most or all of this torque; rather, any torque created by the body must be transfered to the hands for it to have any effect.)

At the very end of the swing, the body must make any possible motion to create that last boost of batspeed without regard to its implications (since the ball will have left the bat by then). Straightening of the back arm is generally considered bad mechanics because it brings the bat around with only the arms rather than allowing the body to bring it around. At the last moment of the swing, however, the bat MUST get around. By using the shoulders (specifically, the lead shoulder) to pull the bottom hand and knob AWAY from the pitcher (counter-clockwise for a righty...just imagine it) at that last moment, the top hand is still left to do some work to create that torque. Instead of a simple uncocking of the wrists, why not push with the back arm to aid with that torque? Pushing of the back arm will push the hand "around" the bottom hand, which creates torque.

McGwire does exactly this:

http://www.pichut.org/up/macgif.gif <<<

Hi Yesisbest

Your post is well thought out and I am in agreement that the back-arm must be driving forward for maximum torque to be applied. I have always disagreed with those that believe bat speed is generated solely by the lead-arm “hooking” the bottom-hand back and the back-arm is just going along for the ride. They maintain that in a high level swing, there is no torque being applied to accelerate the bat to contact. They believe the acceleration is strictly due to the decrease in the arc radius (hook) of the hand-path generated from the lead-side.

Pressure censors place around the handle show that is not the case. It shows that as the bat accelerates to contact, the palm of the top-hand is applying a forward force on the handle about equal to that the fingers of the bottom-hand exert pulling rearward.

So, Yesisbest, if we have a disagreement, it may be in what is driving the top-hand and why the back-elbow remains back on some swings and is more extended on others. I maintain that shoulder rotation is mainly responsible for driving the top-hand forward with the arm muscles contributing far less. I also maintain that how far the back-arm is extended at contact is governed by pitch location and how much the ball is pulled (degrees the bat-head is rotated past perpendicular). – What are your thoughts?

Jack Mankin