>>> This is a quote out of a Mike Epstein article on linear versus rotational:
"one shared movement is a weight transfer. The exact definition of linear hitting is the weight begins coming forward in the stride and continues coming forward through contact and follow-through. In other
words, the hitter's weight is one continuous movement towards the oncoming pitch. A FLEXED front knee allows this continuous forward
movement to take place. In rotational hitting, there is also a weight transfer forward in the stride, but once the front heel drops to trigger the swing, the front side is blocked by a RIGID front leg,
and the hitter's linear movement becomes rotational. Body momentum at this point revolves around a stationary axis, preventing lunging"
This is what Yeager also teaches which in my opinion makes him more rotational than linear. However, Yeager is not an advocate of staying back. <<<
Not having a common definition of what constitutes linear and rotational batting mechanics has lead to much confusion. As you point out, Epstein bases his definition on whether or not a batter's weight continues forward during rotation. Since 1999 (before Epstein or Yeager came online), Batspeed.com has defined the difference between linear and rotational principles by the upper-body mechanics the batter uses to transfer the body's rotational energy into angular acceleration of the bat.
The key differences:
-- Linear mechanics is based on the principles of a "Whip Effect" to generate bat speed.
-- Rotational Mechanics is based on the principles of the "Pendulum Effect.
Linear principle -- The batter transfers his weight to a firm front side and extends his hands A to B. As the linear advancement of the hands stops, the energy developed during the stride is transferred to the bat causing it to whip around - like Cracking a Whip.
Rotational principle -- Regardless of the length of stride, the body rotates about a stationary axis. The hands stay back and allow body rotation to rotate the hands into a "Circular Path" which induces angular acceleration of the bat from the Pendulum Effect -- like swinging a ball on a string.
Kupuna, below is a quote from Dr. Yeager and a video clip illustrating the difference between the Whip and Pendulum principles. Since you have his dvds, you can judge for yourself whether he teaches linear or rotational principles
(Dr. Yeager quote)
"If forward momentum is not stopped and if body segments turn at the same time, maximal energy transfer will not result. If one were to attempt to crack a whip by rotating in a circle without stopping the hand, and therefore not transferring energy, the goal of cracking the whip would not be attained. However, if we stop the whip and then allow the whip to sequentially stop down the line, then we'll get the desired result."
Whip vs Pendulum effect