What does 1.2bpf mean on a softball bat?

Answer 1

BPF is bat performance factor or the bounciness of the bat. The higher the number the more bounce a bat has which translates to the ball coming off the bat with more speed and inertia. Sanctioning bodies limit the BPF typically to a 1.20 or less.

Answer 2

BPF is the Bat Performance Factor of a bat.

During testing, a bat is locked into a stationary position and a Baseball is shot towards the barrel at a high velocity. The BPF is how fast the ball goes after it bounces off of the bat. For instance, if the ball goes 10% faster after it comes off the bat, then the BPF is 1.10. Most leagues will not allow a bat with a BPF higher than 1.20 (or 20% higher velocity after it is struck)