As regards the context of the exercise "stuff" I filmed in Orlando: My long experience with both pitchers and hitters is that most do NOT really physically understand how to rotate the trunk/utilize the legs in a manner that facilitates the "whip effect."
Years ago, I began to label this as a "rotational deficit." The reasons for this functional deficit are numerous but one main reason is simple: Most have practiced movement that occur in "sagittal space" [running,walking, jumping] vastly more than moving in the transverse plane.
Vital to high level throwing and swinging is the ability to create rapid/well sequenced rotation of the trunk [hips to scapular complex]. These exercises that I have spent 15 years developing are specifically designed for learning how to develop this kind of movement.
