Posted by: Jack Mankin (MrBatspeed@aol.com) on Fri Jan 16 14:40:43 2009

>>> The hands must be rotating the head of the bat rearward. I can't even concieve the hands moving forward with the lead foot off the ground <<<

Hi Chuck

Reading your post reminded me of how much things have changed in the past 10 years. In 1999, I brought Batspeed.com on line to present the rotational swing model. At that time, almost all coaches from the Little Leagues to the Pros, taught batting mechanics based on a linear model. That model contended that the energy for the swing was generated from the forward transfer of weight and bat speed was produced from the straight extension and slowing of the hands.

The rotational model I presented contended that the energy for the swing was derived from the rotation of the body about a stationary axis. The body's rotational energy was then transferred into bat speed from the hands taking a circular path and torque induced from the hands applying opposing force at the handle. These three principles (Rotation, CHP and Torque) were completely rejected by the entire baseball community.

Professor Adair (Author -- "The Physics of Baseball" and consultant to MLB) wrote that a model based on the body rotating about a stationary axis, "could not hit a ball past second base." This Discussion Board was filled with posts from irate coaches claiming I was destroying kids chances of becoming good hitters. It was a year or so before I received a few posts that agreed with at least one of the three rotational principles.

Things began to change a few years later when video clips of the best hitters become available on the Web. Those clips made it hard for even the most ardent dissenter not to admit these hitters do rotate about a stationary axis and their hands took a circular path. However, the application of torque at the handle was not as obvious in the clips and my use of physics terms (THT and BHT) to describe the mechanics did not set well with many.

Therefore, your understanding that the bat must first be accelerated rearward is a breath of fresh air. But if you recall, it was just a couple years back that I had to show a number of clips (some overhead views) to convince readers that the bat actually did accelerate back toward the catcher. Even with those clips, many were still reluctant to accept it.

I think much the reluctance may be due to the number of posts many of them wrote decrying the "non-existence" of THT. If they acknowledge the existence of the bat's rearward acceleration, they would then need to address the mechanics that produces it.

Jack Mankin