I was watching an older pool video, "Secrets of a Champion" by Allen Hopkins. He was promoting this thing called the "jump tip". It was basically a tip you screwed on the threads of your butt and turned your Butt into a jump cue. The tip radius was very large. I was very curious by this because I had a similair idea to this but my idea was a shortened shaft instead of a shortened butt like most jump cues. I haven't looked online at all for info on this but does anyone know if this cue/jump tip is legal(tip radius too large, using no shaft, etc) Also is the jump tip still being sold and has anyone tried it? I know a lot of rules are different from tournament to tournament but what are the BCA jump cue rules for tip radius, shaft length and construction, and total cue lenght etc.