Posted by: Jack Mankin (MrBatspeed@aol.com) on Wed Dec 29 18:04:22 2004

Hi All

I have noticed in our discussions of swing mechanics that there is some confusion in understanding torque applied during “pre-launch” and how it relates to torque applied during THT and the actual swing. The post below is from the Archives and discusses that relationship. Following the post, I will analyze clips from http://www.youthbaseballcoaching.com/swings.html to show how the two relate.
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Re: THT
Posted by: Jack Mankin (mrbatspeed@aol.com on Mon Sep 8 15:14:35 2003

Question/Comment:

>>> Following is a link to a file with some frames showing my interpretation of THT. Please let us know if this is correct. How do you teach it? Is the que flatten the hands useful? (The file is best viewed in frame by frame mode)

(http://webpages.charter.net/nickkio/THT.mpg

Thanks, Nick >>>

Jack Mankin's reply:

Hi Nick:

In order to generate maximum bat speed at contact, the better hitters first accelerate the bat-head back toward the catcher before rotating and directing their energies at the ball. The purpose of Top-Hand-Torque is to apply forces to the bat that will accelerate the bat-head in an arc back toward the catcher. With many hitters, Bonds and Sosa to name a couple, the bat-head is accelerated back in two phases.

The first phase occurs prior to shoulder rotation and we refer to it as “Pre-launch” Torque. During this phase, the batter starts with the bat cocked forward toward the pitcher and has his hands some distance from the back-shoulder. Bonds, for example, starts with his hands low and forward from the back-shoulder. As he prepares the launch position, his hands (as a unit) are brought up and pulled to the back-shoulder.

The bat-head is being accelerated into the normal launch position by the top-hand being pulled back at a faster rate than the bottom hand (THT). Therefore, the hands as a unit are being pulled to the back-shoulder but the top-hand is moving faster, or, arcing around the bottom-hand. During the pre-launch phase, one can clearly see the top-hand being pulled up and back (or toward the catcher).

The second phase of THT occurs during initiation as shoulder rotation begins. The direction of force applied by the top-hand at initiation continues to be rearward, but shoulder rotation accelerates the hands (as a unit) around and forward. Therefore, once shoulder rotates begins, the hands (as a unit) are viewed moving forward, but the rearward directional force of the top-hand causes it (and the bat-head) to arc around the slower moving bottom-hand.

Many good hitters do not use pre-launch torque in their swings. They apply THT at initiation as described for the second phase. Since they are applying THT as the shoulder starts turning, the hands (as a unit) will always be viewed moving in a forward arc. --- Nick, the clips you are showing have the batters starting with the bat at (or past) the normal launch position.

Note: With linear mechanics, at initiation, the direction of force of the top-hand and the hands (as a unit) are both moving forward. This results in a straighter hand-path and less angular acceleration of the bat-head. --- With THT, the rearward directional force of the top-hand results in the hand-path being directed more parallel with the catcher’s shoulders and into a more circular hand-path (CHP).

Jack Mankin
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http://www.youthbaseballcoaching.com/swings.html

In analyzing the clips of Tejeda (12th row – 1st clip), Sosa (11th row – 2nd clip) and Bonds (2nd row – 4th clip). Note that all of these batters have the bat vertical or cocked toward the pitcher with their hands a good distance from the back-shoulder in their stance. However, as they take their stride and set up their launch position (shoulders ready to rotate), they all pull their hands toward the back-shoulder and have accelerated the bat-head back toward the normal launch position -- in the plane of the swing behind the head.

If you go slowly frame-by-frame, you will note that their bat-head is brought from the cocked forward position, back to the launch position before the shoulder’s rotate. Also, the bat-head is accelerated a good distance before the back-elbow starts to lower. Since the top-hand is being pulled back around a slower moving bottom-hand, that is THT. I refer to it as “Pre-launch Torque” because it takes place before the launch is initiated.

A key point to note – With all three batters, the bat head is being accelerated rearward from its forward cocked position without shoulder rotation or the lowering of the elbow. The acceleration was from the shoulder and forearm pulling the top-hand rearward.

Jack Mankin