Posted by: Jack Mankin (MrBatspeed@aol.com) on Mon Mar 21 12:31:59 2005

>>> I would like to know the difference in acceleration of the bathead between linear and rotational mechanics. Does one method reach its top speed before the other? Does the acceleration before contact produce a straight line or does it get to that top speed and maintain its velocity? <<<

Hi JRR

In order to answer your question, we first need to define the forces acting on the bat that produce the angular acceleration of the bat-head and secondly, define what constitutes linear and rotational mechanics.

Other than the effects of gravity and drag due to the airflow and other minor factors acting on the bat, there are two main forces that determine the acceleration of the bat-head. (1) The angular displacement of the hand-path induces angular acceleration of the bat-head. (2) Torque: the angular acceleration of the bat-head induced from the hands applying force at the handle from opposing directions.

This Site defines the difference between ‘linear’ and ‘rotational’ transfer mechanics by the hand-path produced and the forces applied at the handle during the initiation of the swing. Rotational transfer mechanics produce a more circular hand-path and the force applied through the hands at initiation is from opposing directions. Linear mechanics produce a straighter hand-path and the force applied through the hands at initiation is more in the same direction.

Rotational transfer mechanics fling the hands into a circular path and apply force through the hands from opposing directions at initiation. Therefore, these mechanics would accelerate the bat-head into the swing plane much earlier in the swing than mechanics that produce a straighter hand-path with forces applied in the same direction.

Many young players are still being taught that if they just transfer their weight forward and quickly extend their hands, there will be a “crack of the whip” effect to accelerate the bat-head. Nick has a couple of clips on his web site ( http://webpages.charter.net/nickkio/HandPath/ ) that show the bat-head’s reaction to a straight and circular path.

Take a look at the clips above and then this clip (http://webpages.charter.net/nickkio/HandstoBall/Linear05.mpg ) showing a batter using linear mechanics to extend the hands (and knob) in a straighter path. It is obvious that both hands are applying force in the same direction until late in the swing. – With an open mind, ask your self -- When the lead-hand nears full extension, is the bat-head being accelerated from a “Crack of the Whip effect” or “Torque” - (top-hand driving past the bottom-hand)?

Jack Mankin

Note: Nick's CHP clip does not move for me but the SHP does.