This is one of the best [tag]youth baseball hitting drills[/tag]. It teaches that the follow through is important to get the most fluid and powerful swing. If you are trying to stop the bat, the swing loses momentum as you slow the bat down.
What you need (set up): You need a tee for the batter to hit from, and you need a ball set up (either on a tee or other apparatus) that will be along the proper follow through plane of the batter.
How this drill works: When a batter swings through the ball, they will maintain their swing plane through the drill and first hit the ball on the tee in front of them, and then on the tee in their proper follow through plane.
If a player is not hitting the second ball then the coach must help them achieve the appropriate swing plane.
This is also a great [tag]baseball[/tag] drill to experiment with different swing planes and swing directions when teaching opposite field hitting.
Results: Having the appropriate swing plane will help the batter achieve more consistency in their battings, and ultimately help them achieve a fuller swing, which assists in increasing overall power.