A fighter's resume is the best way of measuring how great they are. What fighters have the best resumes of all time? Muhammad Ali (Foreman, Frazier, Norton, Liston, Patterson) Sugar Ray Leonard (Hearns, Duran, Hagler, Benitez) Salvador Sanchez (Lopez, Gomez, Nelson) Maybe not as many or as great as Ali or Leonard's wins, but Sanchez beat 3 future HOFers by the time he was 23. Sugar Ray Robinson (LaMotta, Basilio, Fullmer, Graziano, Turpin)
Robinson in the 20th century and Pacquiao in the 21th. Sanchez has the best track record for a 23 or under 25 boxer.
If he had lived, he could have fought and beat Pedroza and Lockridge, then moved up to 130 and fought and beat Limon or Serrano. Wins over 4 HOFers, a 2 weight world champion, and an undisputed champion in 2 weight classes (WBC and WBA were the only titles back then) at 24-25. He would have been top 10 all-time.
Jersey Joe Walcott x2 Billy Conn x2 Max Schmeling Jim Braddock Jack Sharkey Max Baer Primo Carnera Guess whose resumé this is.
Roberto Duran not mentioned yet. Julio Ceasar Chavez. Whitiker if you include his screw job losses and draws. Jack Johnson