Players hear from their coaches all the time, "keep your head down and watch the ball hit the bat." The reality is that it's impossible to actually see the ball hit your bat. As a hitter, you need to make up your mind if you're going to swing about 15 feet after the ball leaves the pitcher's hand, and that's what we're going to simulate with this drill.
So we'll have two tee's set up, one at home plate, and then another one which is about 15 feet in front of home plate.
The purpose of this drill is really to just keep the head up through our swing and working through center field because if the head goes down, the barrel is going to go down as well. With hitters that keep their head down, you'll notice that the spine starts to curve and they lose their posture, which also completely changes the hitters swing path as well.
While doing this drill, make sure the hitter keeps their head up, focusing on the second ball while hitting the first one.