This is presented as a scientific analysis of the baseball swing, based on the research and ideas of Jack Mankin. To develop his scientific approach in the 1990s he studied pro batters, videotaped swings (at normal speed), and had his findings reviewed by at least one physics professor. He believes there is a key aspect of the mechanics of the greatest hitters that we fail to teach to our young players.


The key to bathead speed is the direction and momentum of the forces applied through the body.

1. Keep the body balanced and centered over a vertical axis from head through tailbone.
2. All movement happens at the same time.. Back knee in and back foot pivot, torso and shoulders rotate which lets arms get bathead into final, horizontal arc.
3. Torque is created when front shoulder pulls bottom hand back and rear shoulder drives top hand forward. That's where the added speed comes from.
4. Head and chin have stayed stationary as body moves front shoulder around and brings rear shoulder forward.

Every coach says 'pop the hips' or 'keep your shoulder in there' or 'hit down on the ball.' What if I pick up a bat and 'popped' my hips while holding my shoulders still; would I develop any bat-speed? Shoulder rotation is just as important as hip rotation. Now, suppose I pop my hips and rotate the shoulders but keep slack in my arms so the hands don't move. Do I generate any bat-speed?

No matter what batting technique we choose, the only impact on bat-speed is when force is transmitted through the hands to the bat.

Lateral and rotational movement do not happen at the same time. Some batters move laterally in preparation for the swing. But once the swing starts (hands movement and rotation is initialized) there's no further forward movement of the body. Examples: Barry Bonds and Ken Griffey Jr. have little or no forward movement even in their timing step - they pick up the toe and set it back in the same spot.


As the batter prepares for the swing, the lead knee, hip and shoulder should rotate slightly away from the pitcher. This should bring the hands, center of axis, and pitcher's mound in line. This is not a 'coiled' position. We don't want to stretch muscles around locked joints.

The batter completes his timing step and the body rotates to a good launch position. Now, take a stake, drive down through the bead and body, out the butt and into 6 feet of concrete; this is the axis he will rotate on. All muscles of the body should be attuned to creating rotation around this stationary axis. All thoughts of forward or lateral movement should be expelled. The head will remain perfectly still as the body rotates under it. Forces from the ground up will cause the knees, hips and shoulders to rotate as if they were in a cylinder.

It's important to remember that rotation around a stationary axis is generated from the ground up. The rotation of the hips and torso comes mainly from the action of the legs, knees and feet. Rotation is not generated from the actions of the arms or swinging of the shoulders.
 

• 'Rotational energy' can't be efficiently transferred with 'linear mechanics' (i.e. pushing the top hand toward the pitcher).
• The swing is initiated by the rotation of the body around a stationary axis. The acceleration of the hands is the "result" of rotational energy.
• By initiating the bat properly, the average tension-free swing of a great hitter generates enough bat speed to clear the fence in almost any direction. His main concern is timing and getting the plane of his swing in line with the path of the ball.
• To convert from the 'weight transfer' swing to a 'rotational' swing requires a change in mind-set. Traditional batting mechanics is top-down. Rotating around a stationary axis is a 'ground-up' movement where the knees, hips and shoulders all rotate in unison. The hands are accelerated from the energy of the rotating shoulders.

'Crack of the whip' - As swing begins, batter strides forward transferring weight to a stiff front leg. As hands accelerate, force from bat reaction - transmitted through hands and arms - slows the body's forward motion and rotation. As the body slows, the hands slow to a near stop. Kinetic energy is transferred to the bat as forces uncock the wrists.

'Quick hands' - Testing proves a player swings a bat very much like a weight on the end of a rope. So force at the handle is not transferred to the point of contact. To test - eliminating torque supplied through the hands from acting on the bat - attach a steering wheel knob to the handle of a bat. Accelerate the bat, using the knob, to 15 MPH (22 to 24 inches in about 1/5 second). Batter's weight shift 18 inches forward.
From old theory, bat head should undergo a marked acceleration as forward hand/body progress slows and kinetic energy is transferred. But test after test (overhead camera, 30 fps,1/1000 speed) shows that as the hand-path straightens and slows, there's no further acceleration of the bat.