pro fighters split with managers/trainers and promoters

How does a pro fighter's pay get split between the fighter, manager, and promoter? What's the going rate? I've heard that 33 1/3 percent is the max a fighter should give but does that include everything like a cut man and the promoter? What if a trainer/manager wants 40 percent is he trying to rip the fighter off? I've tried looking this up online but I haven't found much on it. If anyone knows a website to go to for this information or if they know from experience please share it.

Fighters purse is subject to the following deductions (in britain)

Trainer - 10% of gross purse ( this applies to most contests but seperate arrangements of a fixed fee are now made when purses reach a high level).

Manager - 25% of remaining purse after all reasonable expenses that the boxer has incurred (trainer , cutsman, etc) have been deducted.

This is the BBBC standard formula. I don't know how they do it elsewhere.