In the 1981 unification match with Thomas Hearns Leonard had a detached retina, he got it fixed of course but after fighting Bruce Finch in 82 he retired then comes back in 84 to retire again and then Hagler in 87 etc we know the rest. What if he had not sustained that injury against Hearns does he keep on fighting for a few more years?
No. I think SRL could have come back earlier. IMO he was waiting to age Hagler out. He may have had some eye issues but i don't think they were severe enough to merit a lengthy retirement. So i think he might have had 1 or 2 more fights, retired, rested and waited for Hagler to age out.
IMO, without detached retina Sugar stays in the game for 1- 2 more years just because there was so much money available for big fights agains the other kings (with the exception of Hagler). In this alternative timeline the rematch with Hearns and the third bout with Duran happen sooner than they did in real life, most probably around 1982 - 83. I wouldn't even discard a rematch versus Benitez around 1982 or even 83 when Benitez was already faded. Drop a couple of journeyman bouts in the mix and that is enough to keep Sugar honestly busy and making mad money for a couple of years while allowing Hagler to age. On what I agree is that Sugar won't look for Hagler before the Mugabi fight, only in that fight Sugar's eyes opened to the realization that Marvin was beatable after all. Thus, in this alternate timeline Sugar fights regularly during 1982 - 1983, but he still retires in early 1984, returning to the real timeline. He is gone until 1987 when he comes back for Marvin.
