legal bats

[raresco]

Can someone please tell me what dimension bats are legal for a modified-pitch league? In the years I've been playing, we've always used bats with normal-sized barrels, which were usually around a -5. The team I played last night clearly had a fast pitch bat - where the barrel started about four inches from the handle and put batters at a pretty good advantage due to the reduced weight and bigger sweet spot. I would imagine that those type bats are only for fast pitch, but maybe I'm mistaken...