Honestly. Its baffling. Everybody knows and accepts Ali as the greatest... The overwhelming majority of people have no idea who Robinson is. You could also argue that certain fighters were lucky enough to be optimal for particular weight classes, whereas other possibly better fighters might be stuck between weight classes due to their build... They drew the shorter straw. Heavyweight leaves no doubt. Weight classes just give the rest of the mere mortals a chance to shine where they otherwise wouldn't. Thats why I find it funny how anybody could call Jones the GOAT with Cain standing right there 15 feet away in the stands. Its the most prestigious belt for a reason, and by far and away the hardest to hold on to as history has shown us.