Wondering what the difference is between a BBCOR, a BESR and an ABI? Want to know what's legal and what isn't?
You came to the right place.
BESR (Ball Exit Speed Ratio)
This is a longstanding test used to ensure that non-wood bats play similar to wood bats. It tests a bat's "exit speed," i.e. how fast the ball bounces off a composite or aluminum bat barrel. It has been phased out.
The BBCOR Bat Standard (Batted Ball Coefficient of Restitution)
This is a new, more-accurate test used to ensure that aluminum and composite bats play similar to wood bats.
Instead of measuring the speed of the ball after it is batted, BBCOR measures the "bounciness" of the ball and bat, or the "trampoline" effect. When a bat hits a ball, the ball actually compresses / deforms by nearly a third at high pitch velocities.
Testing is done by WSU Sports Science Lab and a list maintained at their website.
ABI (Accelerated Break-In Test)
This is a test performed on bats to simulate heavy use. Composite bats perform better the more you use them, so when combined with the BBCOR, the ABI ensures that even with heavy usage, composite bats perform similar to wood bats.
Now in effect - All bats used in the NCAA and any organizations that follow NCAA rules (such as the NAIA), must be BBCOR certified. The BESR certification is no longer used.
Composite-barreled bats, which were previously banned in the NCAA, will be allowed if they can pass the BBCOR test.
Starting Jan. 1, 2012 - All bats must be BBCOR certified. The BESR certification will no longer be used.
Composite-barreled bats, which were previously banned, will be allowed if they can pass the BBCOR test.
California high schools
Now in effect - All bats must be BBCOR certified as listed on the NFHS website.
All non-wood bats must carry no-tamper decals.
Here's a list of the latest bats that will be legal in leagues that require a BBCOR certification.