Posted by: Jack Mankin (Mrbatspeed@aol.com) on Sat May 3 09:36:27 2003

>>> I went on the explain that I had tested this theory with my 16 yr olds at fall practice and that everyone of them registered higher batspeeds at extension than at the "L". It was about this time that I posted a clip of Arod (the same on Ray Porco and I have been discussing) and the topic died a silent death. <<<

Hi Teacherman and Bart

Below is a post that may add to your discussion.

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Re: full extension
Posted by: Jack Mankin (MrBatspeed@aol.com) on Tue Jan 15 01:27:58 2002

>>> jack.....if i'm not mistaken, i think that in the past you have stated that most major leaguers do not achieve full extension of the bottom arm at contact....i'm under the impression that you feel that at contact the bottom arm is in the "L" position.....

however, out of the 90 or so video clips that i have, of the ones that i can clearly see the bottom arm when i freeze at the contact frame, i find roughly 1/3 have their bottom arm in an "L" position, about 1/3 are somewhere in between the "L" position & full extension, and about 1/3 are at FULL extension......

would you mind clarifying your position? respectfully, grc. <<<

Hi grc

I would agree with your evaluation of the back-arm positions for major league hitters. If my study differs from what you found, it would be that you're finding 1/3 of the clips showing the back-arm in the "L" position at contact was a higher percentage than I found. Only one out of five hitters could attain that position in the late 1980's. This would support the theory that a greater number of Major League players are using rotational transfer mechanics today than in the past.

As Major Dan pointed out, all hitters (3/3) will have the back-arm more extended on more outside pitches. But, even on pitches down the middle, I would be surprised if more than 1/3 of today's pro hitters bring the bat to contact with the back-arm in the "L" position. This, along with lead-shoulder pull, is the mark of a hitter with real power for pitches from the middle-in.

The "L" position of the back-arm and the lead-shoulder pulling back at contact are the key components in generating the "hook" (coined by Paul Nyman) in the hand-path. The "hook" indicates the arc radius of the hand-path is rapidly shrinking which maximizes the transfer of the body's rotational energy to the bat, and greatly increases the bat's rate of angular displacement. The "hook" also indicates maximum bottom-hand-torque is being applied to the bat. -- In other words, great bat speed is being developed when these two positions (the "L" position and lead-shoulder pull) occur.

Average hitters apply a good deal of torque to the bat by driving the top-hand past the bottom-hand. But, the farther the back-arm extends to produce the torque, the more sweeping the hand-path becomes -- and therefore producing less "hook" effect. --- The better hitters apply torque by using lead-shoulder rotation to pull the bottom-hand around the top-hand (back-arm in "L" position). This pulling back action also generates the "hook" effect.

Therefor, the average hitter may apply as much torque to the bat as a better hitter, but his sweeping (or straighter) hand-path does not transfer as much of the body's rotational energy. To become a great hitter requires both torque and the transfer of rotational energy. --- Note: For maximum "hook" effect -- the "L" (1), pull back (2), and contact (3) - must occur simultaneously (or together).

Jack Mankin