Posted by: Jack Mankin (MrBatspeed@aol.com) on Sun Jan 23 22:32:22 2000

>>>I don't come around to often, but I really like your site, and your info. I'm just confused about the front arm discussion. Do you suggest the front arm should be stiff like griffey's, or bent like Derek Jeter's? Also, I'd like to know where to find out what you mean by angular displacment.<<<

Hi Zack

Thank you for complementing the site. --- “Angular displacement” denotes the bat is rotating around a point. If the bat is started pointing at the catcher and rotates until it is across the plate, that would equal about 90 degrees. Or an angular displacement of 90 degrees. In most cases you can use the rate of angular displacement in place of “bat speed.”

Zack, I am not concerned with the lead arm having some bend while in the launch position. I certainly would not recommend the arm being so rigid as to create tension. My main concern is that the forces the batter applies to the bat with the hands at the start of the swing do not cause the lead elbow to bend and point toward the pitcher. Driving the hands (with the arm muscles) across the body to keep the swing compact is the makings of a weak swing.

If the batter applies the correct forces (rotational & torque) to initiate the swing, this will aid in overcoming the bat’s inertia and the lead arm will become fairly straight by mid-swing. It is very important in developing bat speed (or angular displacement) that the first direction of movement of the hands not be directed back toward the pitcher. --- Below is a post I made earlier on this subject.


>>> Something I was writing today for the video may help in his advancement. I was discussing the “inward turn” and why it was so important to a good swing. --- The inward turn is just that, a turn. It’s not the shifting back of the axis or the hands. It’s a turn. There are two main benefits that result from this move. The shoulders will rotate somewhat more than the hips during the turn. This stretches the muscles of the torso so that there will be less slack when the hips start to rotate. But even of more importance is the position the turn brings the hands to. The hands, center of axis and the pitchers mound should be inline at the start (first movement of the hands) of the swing.

The forces applied to the bat during initiation produces trajectories that will set the tone for the entire swing. It is very important that the first directional movement of the hands be perpendicular (or as close as possible to it) to the line of flight of the ball. This will induce the greatest amount of angular displacement into the bat and propel the hands into the correct path. ---The inward turn should bring the hands, center of axis and the pitchers mound in line. If the batter will allow the rotation of the body (stationary axis) against the lead arm to accelerate the hands, their first movement will be perpendicular to the flight of the ball.

The top hand can also aid in getting the hands started in the correct direction. We will discuss this later. Hope this helps. It’s a lot easier to show than write about swing mechanics.<<<

Jack Mankin