When taking baseball instruction on hitting mechanics you will find two different approaches and philosophies.  Rotational hitting vs. Linear hitting.  Now if you are new to the baseball hitting mechanics world, or are just unfamiliar with the terminology, let me offer an explanation here of the rotational hitting approach.

Rotational Hitting

First, the entire goal of a fundamentally correct baseball swing is to generate the most energy into the baseball as possible.  In order for this to occur, there are a certain pattern of movements that must happen at the correct time in order for maximum energy to be achieved.

A rotational approach to hitting suggests that the energy created in a baseball swing stems primarily from the back portion of the body.   And more specifically the power is generated from the lower half of the back side with the knee and hip.  The hitting process begins with the back side rotating and bringing the hands into the contact zone.  If the right timing is achieved, this approach transfers an immense amount of power into the pitch.  On the flip side, incorrect timing of the back knee and hip will produce a sluggish swing. 

Steps to a rotational baseball swing:

First, a hitter needs to create a good weight shift to the back leg directly from the stance postion. Special attention should be taken to make sure this weight shift is not purely lateral in motion.  Doing this will create imbalance and a weight distribution problem in the next step.

The second step is the trigger process.  This is the movement that separates a rotational hitter from a linear hitter.  The triggering process (the movement that begins energy) should start with the back knee rotating and moving directly towards the pitch (as opposed to simply spinning in place).  The back hip will quickly follow the back knee in the rotation process.  In actuality it looks as if the back knee and hip are moving at the same time.   While this is the case, mental focus should be placed on the back knee and thigh movement first.  Finally, the hands which have been lagging behind the lower body some will begin to enter into the hitting zone.  It's imperative that the hands do not begin the swing since power in the rotational philosophy stems from the back knee and hip first.  The hands then become the secondary source of power.  Early hand movement would limit any effort to use energy from the back side of the body.

The final step to the rotational approach occurs as the bat enters the zone.  The common tell tale signs of this philosophy can be found in the balance points.  The easiest to explain in writing is that as the hitter comes in contact with the pitch there will be an imaginary vertical alignment with the inside shoulder joint, the back hip, and the back knee joint.  This positioning demonstrates that a hitter’s balance remains in the center of his body rather than shifting forward as seen in the linear style of hitting.

It should be noted that rotational hitting is used by most all major colleges and a overwhelming majority of Major League hitters.  The reason being is that the rotational style allows hitters to experience the most consistency while maximizing their power numbers.