Earlier posts described the stance and the pre-swing loading movement.  The stance is personal choice  but must allow the transition smoothly and quickly into their swing.  Loading shifts the batter's weight and hands backwards to create a greater distance and allow more force to be generated before making contact with the ball.

The next activity in the batter's swinging motion is to generate bat speed through the forward weight transfer and hip rotation.  There are two popular schools of thought to generate bat speed:  linear movement and rotational movement.  The pure linear swing, which is how most parents and grandparents were taught to swing, focuses on generating as much speed from the legs through the weight transfer from the rear side (or back leg) forward by using of a longer stride.  This technique lengthens the time that the bat is in the hitting zone.  Conversely, a pure rotational swing has the batter take a very small stride with the focus on generating more power from the legs and torso with an explosive hip rotation.  This method provides greater power through the strike zone by leveraging the strongest parts of the human body. Proponents of both styles of swinging will claim that they use portions of the other swinging style and that is the crux of the issue.  You need both to generate the maximum bat speed while maximizing the time the bat is in the hitting zone.

Bat speed generation through forward weight transfer and hip rotation
To generate the maximum bat speed, a batter needs to transfer the weight from their back leg forward and rotate their hips.  A batter needs forward linear movement to transfer the power from the rear side into their swing.  They also need to rotate their hips to transfer the power from the strongest part of the body, which is the legs, to the point of contact.  Some batters incorporate more weight transfer (ie., linear swinging) while others incorporate more hip rotation (ie., rotational swinging), but all good hitters use both physical levers to generate bat speed.

Just before the pitch is released, the batter should be loaded and starting their stride forward.  The front foot lands with the leg slightly bent.  The batter begins the weight transfer forward toward the point of contact.  The front leg straightens and stiffens while the hips rotate as the bat goes through the strike zone to the point of impact.

At this point a common question arises:  how much do the hips rotate?  The answer is it depends on the type of pitch and pitch location.  To keep it simple, let us assume all pitches are fast balls and the hitter is a right handed batter.  If the pitch is on the inside quarter of the plate then the hips should rotate so the batter's belly button is facing the shortstop.  If the pitch is on the outside quarter of the plate then the hips will rotate less and the batter's belly button is facing the second baseman.  If the pitch is down the middle half of the plate then the batter's hip rotate so that the belly button is facing right back at the pitcher.

A balanced weight transfer and explosive hip torque can transform a weak hitter into a power hitter that hits for a high average.  By incorporating the linear forward weight transfer, the batter keeps the bat in the hitting zone longer.  A powerful hip rotation allows the batter to leverage the strongest part of their body, the legs, to generate greater bat speed through the strike zone.

Next Step:  The Swing