Both at their bests, very competitive fight, but I'll go with Walker Smith. Robinson might not have been as mobile as Leonard, but it evens out because he was more powerful, stronger, and had a better chin than Leonard. Hagler might have had the best chin ever, but if he gets hit with Robinson's best I have no doubt he would feel it. Robinson was pretty tall too, he was 5'11. His height, range, coupled with his quickness pose a lot of problems for Hagler. Obviously, Hagler poses a lot of problems for Robinson as well, but I'll go with the GOAT by UD.
