???

That is kind of a tough question to answer because a great many trainers were boxers at one time. Take Eddie Futch, one of the greatest. He was an amateur, but never was able to turn pro. Beristain also boxed but his career was brief due to an eye injury. The older Mayweather brothers Roger and Floyd are accomplished trainers who were pro fighters. Freddie Roach comes to mind. You can't mention boxers/trainers without mentioning Manny Steward.

Jack Blackburn.

Teddy Atlas.

Freddie Roach.

Roger Mayweather.

Charlie Goldman.

Georgie Benton

James Mcgirt

1. Stewart

2.Freddie Roach

3.Eddie Muhammad

4.Julian Jackson

5.Roger Mayweather

???