Posted by: Jack Mankin (MrBatspeed@aol.com) on Fri Apr 6 08:59:22 2001

Hi DC & Dick

Your questions (posted in March) regarding the bat’s pivot point deserve a reply. The reason I did not address them at the time is because I do not think it is helpful to discuss to many important topics in the same thread. We were discussing the role of the arms in the swing and I didn’t want the theme of the message to be distracted by other topics. --- So I will now address them below.

>>> Secondly, are you sure the pivot point is between the two hands? If that were the case, I would never be able to swing with only my lead arm. I took a whiffle-ball bat, held my lead HAND and arm stationary, then created angular displacement by moving thru the range of my wrist. My top-hand wasn't on the bat to help create angular displacement. What was my lead hand pivoting around if I didn't have the top hand on the bat to create opposing torque forces? Thanks for helping to clarify these items for me. DC <<<

Hi DC

DC, you can apply torque to the bat while swinging it with just one hand. The muscles in the forearm cause the wrist to turn. As the wrist turns, the small-finger-side of the hand is pulling inward as the thumb-side is turning out. So once again there was forces being applied from opposing directions – torque. The pivot point in this case would be in the center of the wrist.

It would seem logical, that if a fair amount torque could be applied with just one wrist, then a good deal of torque could be applied with both wrists. But just the opposite is true, the wrists can apply very little torque (or snap) to the bat when held in both hands. --- When just one hand is on the bat, the hand is free to rotate about a point in the wrist. But, when both hands hold the bat, each hand wants to rotate around a point in its own wrist. Not having a common point of rotation results in the wrists having very limited movement with little torque supplied. --- You can check this out for yourself – grip the bat and place both elbows on a table – note the limited range of wrist movement when the push-pull movement of the forearms is limited.

So as I have stated before; what we usually refer to as “snapping the wrist”, is actually the push-pull action of the forearms – the wrist remain fairly straight.


>>>"Secondly, are you sure the pivot point is between the two hands?"

Jack I may have missed it, but have you answered that question?
I'm wondering if you consider the no contribution to bat speed is offerd by rotation about the lead wrist? Dick Anthony <<<

Hi Dick

The location of the pivot point depends on the swing mechanics used. In a backside dominant (more linear) swing, the back-arm is always pushing the top hand around a slower moving bottom hand. So, with these mechanics the bat’s pivot point would be closer to the lead hand. But this produces a longer hand-path and much of the bat speed is developed after passing the contact point.

With the better hitters, the pivot point progresses from lead-hand at initiation to the back-hand at contact. ---While the batter is applying top-hand-torque at initiation, the top-hand is pulling the bat-head (back toward the catcher) around a more stationary lead-hand (pivot point closer to the lead-hand). --- During the middle part of the swing, the push-pull of the arms is more equal (pivot point more between the hands). --- Coming into contact, the pulling back of the lead shoulder causes the lead-hand to pull the knob of the bat around a more stationary back-hand (pivot point closer to the back-hand).

The “hook effect” in the hand-path occurs as the lead shoulder pulls the bottom-hand back toward the catcher (bottom-hand-torque). --- Driving the top-hand around the lead-hand results in a larger arc radius of the hand-path (no hook effect).

Jack Mankin