The Shoulders. Track with the front get on plane with the back.

As a hitter your front shoulder is your scope. You should try to line it up at release point like the scope on a riffle. Many hitters over rotate their front shoulder forcing themselves to commit to swinging earlier. A reminder that the biggest thing a hitter can create for himself is time and when you have to commit to swinging early the baseball is not close enough to read if it is a good pitch to hit so you really are just guessing. You want to keep your front shoulder tracking the ball as long as possible. When you eyes tell you its time to swing, instead of "throwing your hands at the ball what you want to do is bring your back shoulder down to the height of the ball. This allows you to "get on plane" or "swing level" You do not want to swing down at the ball. Coaches teach this because they think swinging down is the shortest distance but all they are doing is forcing their hitters to have perfect timing to make solid contact. Here are some still pictures from homeruns last night. Notice how they line up their front shoulder with the ball and then take their back shoulder down to the height of the ball. The shoulder angle is more steep when the ball is down compared to a more elevated location. More to come soon.