Posted by: Jack Mankin (MrBatspeed@aol.com) on Fri Jul 25 12:53:54 2008

>>> Jack - those videos are very helpful in explaining and showing BHT. I have pictures of my son at the lag and contact position that I believe show my son is using CHP, BHT and lead shoulder pull-back effectively. I am looking forward to the THT videos and any comments you might have on how to teach it. Thanks. <<<

Hi Dave

I will show clips of the principles involved in applying THT early next week. In the meantime I will give you a preview of important points in effectively implementing the mechanic.

Other than gravity, there are two main factors involved in generating the bat-head’s rearward acceleration. (1) Torque induced from the top-hand applying a rearward force as the bottom-hand is pulled forward by lead-shoulder rotation. (2) Torque induced from the rotation of the back-forearm (and hand) as the elbow lowers. -- Hold the bat at the launch position with only the top-hand. Note that by holding the hand up in a fairly fixed position, you can accelerate the bat-head rearward by rotating the forearm as the elbow lowers.

One of the major problems I find with hitters THT mechanics (MLB included) is they reply to heavily on rotating the forearm without the top-hand applying a rearward force during initiation. This results in the back-forearm driving down and forward toward the batter’s side, which creates slack in the lead-side. Lead-shoulder rotation is now mainly used in taking out the slack rather than doing work. This action depletes most of the shoulder rotation with little left for applying BHT.

Note: The above illustrates the importance of a key transfer principle – The role of the forearms and hands are to remain back and apply torque. The acceleration of the hands and arms around the swing plane is powered by shoulder rotation.

Jack Mankin