Is there a minimum weight that a fighter can weigh into a fight? Example Floyd showed up at about 150 to fight Oscar at 154..Not much of a difference. But lets say a fighter wanted to fight 10lbs under the weight to keep his speed etc.. What then? Did Roy Jones have to fight John Ruiz weighing 200lbs or could he have weighed 190 for it? For a fighter with the speed and athletic ability of Roy Jones he could have beaten fighters 20 lbs heavier than his own body weight off speed alone..But I really don't see why a fighter wouldn't be allowed to fight at any weight under the mandatory weight because when you got fighters like Valuev outweighing his opponents by like at least 60-70+ lbs then why should it matter for the rest?
Unless there is contractly agreed minimum, a fighter is perfectly entitled to weigh as little as he wants under the weight limit.