Posted by: Jack Mankin (mrbatspeed@aol.com) on Wed Mar 3 15:18:47 2004

Good progress.

Numbering frames would be very nice.

A few nits to pick:

frames 1,2,3: usually see bat tip toward vertical a little when hands drop, due to internal rotation of back arm

frames 4,5,6: would like to see back elbow appear behind back as it goes up back and down, and not disappear until about frame 7

Would expect hips to keep turning,not just go up in frames 7,8. <<<

Hi Tom

The frames are identified in the frame-by-frame. Frames A, B, C, D, and E are the pre-launch frames. That actual swing, from initiation to contact, are frames 1, 2, 3, 4 and 5. Frames X, Y and Z are of the follow-through.

These are computerized drawings taken from 13 frames of a well known Major League batter, hitting a ball over 500 feet. These are his typical swing mechanics. If internal rotation of the back-arm would cause his bat to tip toward vertical a little when hands drop, it would be in his frame-by-frame video clips and therefore, in the computerized tracings. The same is true regarding his hip rotation.

Tom, I just rechecked the entire swing frame-by-frame. The back-elbow movement in the video is the same as the computerized traces. I have also commented on seeing the elbow as it lowers on right-handed hitters. However, you can not see the elbow of a lefthander because those shots were taken from the left-centerfield angle.

The swing used for the drawings is shot from almost straightaway centerfield – very slightly to right-center. We started to use clips shot from left-center but that angle did not allow us to see the hand movement coming to the back-shoulder as well. I wish we could show both views, but that is just not practical.

Jack Mankin