Posted by: Coach Tom () on Mon Mar 19 22:15:04 2001

Jack,

Your explanation on shoulder rotation as the key to understanding and reviewing a swing was superb and very enlightening. Therefore, I hope you don't mind, but I copied your post and brought it to the top because it seemed so important and such a benefit to all.

Also, your instructional video was everything that I hoped for, and swing review analysis opened my eyes to problems that I never knew I had in my swing, and now I've fixed the problems you discussed and am developing a much more powerful swing. Thanks Jack.

Jack's Post:
"Some of the main things I need to see when reviewing a swing on video is pitch placement, degree of inward turn and the swing plane. A batter’s mechanics change with pitch placement and it, along with the swing plane, is better viewed from the front. Although much can be learned from a side view, I would still say that if only one view is available, I would take the front view. It might help if I explain what I look for in a swing.

When I started the study I had no idea of what a good swing should look like. But neither was I locked into any preconceived mechanics that I thought would be better than others. Nothing I had previously taught batters over the years seemed to be of much value in helping them to gain pop in their bat. So I started the study to see if there were identifiable mechanics used by the better hitters that was not evident in lesser hitters.

It took three or four months of trial and error to work out a system where I could chart a hitter’s mechanics (from televised games) and enter the data into a computer. I logged 32 components of a batter’s mechanics, such as: how long was the stride – angle of the lead foot at footplant – placement of the hands at launch – hip and shoulder rotation – 6 were to identify limb and body positions at contact – and so on. --- Over a period of two years I charted close to 3000 swings.

I found that there are 3 traits found only in the very best hitters, those hitters who can hit for both power (30+ HR) and high batting average (.300+). --- (1) They have shoulder rotation that continues through contact. (2) They initiate the swing with top-hand-torque or exhibit bottom-hand-torque at contact, or both. (3) Their bat stays on a clean (no dips or waves) swing plane.

(1) They have shoulder rotation that continues through contact. --- Hitters with little power complete shoulder rotation with the bat 60 to 90 degrees (2 to 3 video frames) from contact. The bat is brought to contact by the nearly full extension of the back arm. – Average and better hitters will bring the bat closer to contact before completing rotation (usually 1 frame before contact). This means the better hitters will require less extension of the back arm to bring the bat to contact. – Only the great hitters initiated the swing with trajectories that will have the lead shoulder pulling back toward the catcher through contact. Their back arm will form the “L” position at contact. The elbow will be at 90 or 110 degrees depending on whether they hit the ball straight-away for pulled it. – NOTE: This is true for pitches in the middle 2/3’s of the strike zone. Average hitters that are jammed will suck in the arms and rotate the shoulders through contact, but I think you can see the difference. Also, hitters like Big Mac, who set up to hit outside pitches, will not get as much lead-shoulder-pull at contact.

Although good lower body mechanics is obviously very important in developing shoulder rotation, I could not find that single trait that separated the average hitter from the great hitters. Some great hitters took longer strides, some took little or no stride. Some had more open hips and lead-foot at foot plant - some were closed. Having the lead-leg extending at contact was found with the great hitters, but there were also some average hitters who did the same thing. The great and the average hitter rotated around a fairly stationary axis. -- Shoulder rotation through contact, regardless of how it was developed, was the important factor, and created the greatest results.

(2) They initiate the swing with top-hand-torque or exhibit bottom-hand-torque at contact or use both. --- Only hitters (like Big Mac) that can generate a lot of early bat speed with top-hand-torque can hit the outside pitch with real authority. They delay shoulder rotation while accelerating the bat-head. This results in lead-arm casting out to a wider hand-path and less shoulder rotation by contact. --- Batters who initiate the swing with THT and finish with BHT (like Williams, Brett and Bonds) are the batters who can hit for both power and average. --- Batters who have a more static bat as they initiate body rotation (like Matt Williams or Ron Gant) must be able to apply a lot of BHT to develop power for the swing. They exhibit the mechanics of the great hitter on pitches from the middle-in, but are just average to weak hitters on the outer areas of the strike zone where shoulder rotation is limited.

(3) Their bat stays on a clean (no dips or waves) swing plane. --- To maintain consistent contact and bat speed, the swing plane must remain clean and in-line with the lead arm. Mechanical wrist binds from the grip, or not allowing the top wrist to rotate in the plane, will cause dips or waves in the swing plane. I found this a major problem with many great hitters in a batting slump. – As an example: In the early 1990’s, McGwire was in a terrible slump. His batting average was around 200 and his power numbers were also way down. A frame-by frame analysis of his swing showed that he was accelerating the bat-head (with THT) vertically down through the plane of the lead arm. This caused a big bind in the wrist of his top hand. The bat-head dove (or dipped) from what I termed “the reverse wrist roll.” His bat speed was also cut substantially. – Eric Davis (sp) and many other good hitters exhibited similar swing plane problems.

...It would take a book to fill in all the blanks, buts and what-ifs. Nevertheless, I hope this outline helps everyone to understand why the front view is so important.

Jack Mankin"

Keep up the great work, Coach Tom