Sorry this might be a bit of a crap question for you guys but Im not too sure of the finer details of the divisons below heavyweight. In the build up to the Mayweather Alvarez fight I've been reading lots about Alvarez's weight and how during fight night he'll be something like 170 lbs because of hydraytion and with 30 days to go he was still something like 14 lbs over the weight limit. Obviously Mayweather is around 150 lbs, but does weight really make much of a difference to the fight?