>>>If you look at the Skeleton of Big Mac at the web address posted by Shawn under the hip rotation 2 thread, Mac is letting go with the top hand after contact. This seems to keep the bat on plane and allow the shoulder to keep turning back instead of breaking down the front arm. Do you think there is any advantage to this or intending to do this? Does this accentuate the pull back/bottom hand torque or keep things on plane better/longer? <<<
First of all, I would like to make a couple of commits regarding the "Skeleton" action they showed (McGwire vs Amateur Hitter
). -- I was curious as to why they showed the two forms in different time frames. They showed Mac's skeleton starting at initiation, shoulders starting to rotate. Whereas, they had the Amateur starting with his stride and his swing initiation (shoulder rotation) starting about 4 frames later.
It was also interesting to note that the mechanics of the Amateur generated greater bat- displacement (about 85 degrees/ frame) coming into the contact zone than did Mac (about 45 degrees/frame). Maybe the Amateur was using a -10 bat.
The last 2 or 3 years, Mac has moved slightly away from the plate and sets up to treat most pitches as being middle-out. This means he plans to use a lot of top-hand-torque well into the swing (forget the Skeleton for a minute, Mac develops great early bat speed). This also means he will have less hip and shoulder rotation and the back arm will be more extended at contact. These mechanics will cause a wider hand-path and full extension of the back arm occurs while the bat is pointing in the direction of the first or second baseman. With the bat sweeping in that direction, the lead elbow cannot break down-and-in. Therefore, it would require a sudden change in the direction of the bat's momentum (hard jerk to the wrist) if he attempts to keep both hands on the bat. Releasing the top hand and allowing the bat to coast out in a wider arc will eliminate this.
The lead elbow will break down-and-in for batters who have their back arm reach full extension as the bat is sweeping past the pitcher. Here the bat's momentum is directed more toward third base and the batter can keep both hands on the bat.
Note: The release of the top hand normally occurs well after contact and therefore has little impact on bat speed.
Note: Batters who limit hip and shoulder rotation by casting to much weight forward onto the front leg may also find it necessary to release the top hand.