Tough to pick one of all - I'd say Dundee for his work with both Ali and Leonard. I really like Futch's coaching record in developing Frazier, Norton, Holmes and Bowe as they were quite different HWs from each other but Futch made the most out of developing of their talents. Have to give special mentions to D'Amato and Steward. I've heard very little credit given to Usyk's trainer Lapin despite Usyk's recent successes.
Either Futch or Arcel imo both developed so many great fighters its actually insane the others usually had one or two standouts but not as many as those two.
Kenny Adams is undoubtedly an ATG trainer yet very seldom receives his flowers for his tremendous work with over 50 world champions and with the American national amateur boxing team. Ismael Salas deserves far more praise for his work with the Cuban national team and for his work with fighters like Kazuto Ioka, Jorge Linares, and Joe Joyce. George Benton was another exemplary trainer who doesn't get the praise he deserves. Most of Lou Nova's best fighters were really nurtured and taught by Benton. Pernell Whitaker was trained predominantly by Benton, as were a number of the other members of his Olympic squad like Meldrick Taylor or Evander Holyfield, as well as Mike McCallum. Freddie Brown was an excellent trainer who gets overlooked too. His work with Duran in particular is often overshadowed by Ray Arcel's presence even though Brown did most of the actual coaching to my understanding. The list of notable fighters Brown guided is quite staggering honestly. Bouie Fisher's work with Bernard Hopkins is very underrated imo. Overall though, I'd probably agree with the general consensus that Eddie Futch is the best trainer in boxing's history. I think Freddie Roach is quite close on the heels of his former mentor though honestly.
