Modern composite bats get better the more you use it. The reason is you are “breaking ” the interior wall of the bat. Contact with every hit is breaking down the fibers and glue that hold the inner wall together. You want to achieve this with every composite bat. Once broken in, the bat provides a trampoline type effect. This will increase the bats pop and will result in faster exit speeds and added distance. In a perfect world, you would evenly break in the bat across the barrel or the “sweet spot.” Unfortunately, this doesn’t happen with natural use.
Breaking the bat in through practice or game use will undoubtedly create “dead spots.” Have you made solid contact with the ball and it doesn’t go nearly as far as you thought? Maybe you have heard that dreaded thud sound and the ball doesn’t leave the infield? Both of those hits are a result of having a dead spot(s) in the barrel of the bat.
On the reverse side, have you been surprised how far you hit a ball? Or watched infielders get out of the way of your sharply hit line drive? That’s because you made contact on the “sweet spot.”
Getting your bat rolled eliminates all “dead spots.” Having no “dead spots” will increase your bat’s durability and longevity. With a rolled bat, the entire barrel becomes one giant “sweet spot.” This will give you (up to) an additional 50 feet in distance and increase the balls exit speed.