Posted by: Jack Mankin (MrBatspeed@aol.com) on Sun Apr 20 15:27:39 2008

Hi All

I have been away from the office or busy with another project and have had less time to respond to your questions or offer my thoughts. Much of my time has been spent analyzing the swing mechanics of college players. My main interest is with the mechanics of players that would be considered “five tool” prospects if their slugging percentages were not lower than required for a high round draft choice.

So far, I have recorded about thirty college games from TV broadcasts. From these games, I captured (MotionView) swings that show an across the plate views as well as the normal frontal views. It requires both of these views of the swing to make a comprehensive frame-by-frame analysis of a batter’s mechanics. I now have data from 102 players’ swing analysis.

One of the interesting observations I noted from the data collected so far is the relationship of the bat’s trajectory at contact to the batter’s slugging percentage. The bat trajectory of batters in the upper tear, .800 and above, were all on an up-slope of around 20 to 25 degrees at contact. I also noted that batters whose mechanics produced a downward or more level trajectory in the zone seldom produced slugging percentages over 125 point higher than their batting percentage.

Although this collection of data is in its preliminary stage, it has led me to further consider the energy transferred to the ball during the bat/ball collision. Professor Adair has calculated that a ball attains its maximum flight when exiting the bat at a 35-degree upward angle (in relationship to the ground).

A bat on a 20-degree up-slope at contact would only need to strike the ball slightly below its centerline to deflect the ball upward the extra 15 degrees. A bat moving level with the ground would need to strike the ball much farther below the centerline to deflect the ball upward 35 degrees. The question then becomes – how much reduction to the ball’s exit speed results as it is struck farther and farther below its centerline.

Hopefully, some of you have the physics expertise to vector these forces. Your input would be appreciated.

Jack Mankin