Bat shaving removes composite layers from the inner barrel of a bat. This removal of material causes the bat to flex more when impacted with a baseball or softball. That flex creates more of a bounce off the bat and increases velocity; which in turn creates more distance and pop to a batted ball. Distances have been scientifically studied to increase batted ball mph to about 8 mph; which equates to 62 ft in distance. So bat shaving basically is a process that thins the bats barrel to gain huge distances by increasing the bounce (flex) of the barrel.
A bat rolling machine breaks up carbon fiber within the bats barrel in order to "loosen up" the barrel for more flex. Composite material is woven fabric held together by epoxy resin and layered for strength. Bat rolling breaks down these layers by adding pressure to the fibers crushing the brittle epoxy resin holding the fibers together. The end results of this breaking down of composite material is an increased flex of the barrel of the bat. This increase causing the batted ball to spring off the bat with a surge in velocity. A scientific study from the Penn State University have proven a rise in batted ball speeds up to 3.5 mph generated by bat rolling. Independent studies has that number as high as 6 mph (45 ft).
Bat Rolling Process
A bat is placed in between 3 rollers and ran through the bat rolling machine both perpendicularly and parallel. There is also other accelerated break in techniques such as: ABI (a device with a hydraulic press that compresses the barrel), natural break in, heated bat rolling, and electric bat rolling. All these techniques are used in our Ultimate Break In of your bats. We have been doing this since 2006 and have witnessed many different composites from every manufacturer of bats. We are definitely the world's bat rolling authority; we have seen it all and rolled them all.
Men's slow pitch softball is what kicked the bat shaving industry into motion. There have been a rumors of bat shavers as early as 2000 but the earliest bat shaver we know of is J.R. Hayseed from North Carolina. The first company to offer this on the web was Juicedbats.com (Late 2005) but they have since folded due to shoddy workmanship. Word spread through the softball community and by 2007 bat shaving had become a niche in the illegal alteration of softball bats. By 2010 it was a process known by 90% of the slow pitch world.
Shaved Softball Bats
Baseball and fastpitch bats are made out of the same composite material the softball bats are made out of and word of the insane increase in distance spread to both types of play. Bat are used for homerun derby showcases and confidence building batting practice just as in slow pitch. The barrel lengths are not normally as long as the 34" slow pitch bats so the distance increases are not as high. You could figure about a 2-4 ft drop in distance per inch lost on the barrel. Big Barrel bats, however, hit better than the 2 1/4 barrel bats because there is more room for flex.