imo, a massive one. Ann Wolfe might be a freak of nature type female boxer, I really wouldn't know as I don't really care to see women fight... But that's just me. I also think there's a steep curve where it becomes more plausible that a woman could win with less of a weight edge.. If that makes any sense.. I.e, sure, there are probably some outstanding female boxers who could beat a top male bantamweight while weighing less than say 30 lbs more... But as soon as the male fighter is big enough, I don't give a rats ass how much heavier the woman is, she's not winning in a ring with gloves.. In other words, it wouldn't make a whole lot of difference if a woman outweighed Bernard Hopkins by 25 or 300 pounds, she would get her ass beat down, brutally. If for no other reason than Hopkins has enough natural muscle mass to KO a person of almost any size with one punch. Ivan Calderon couldn't hurt me with his best shot if I was asleep standing up, you know?.. As soon as your talking below featherweight though then sure, but once the man is big enough to break an egg, it's going to take some sort of freak of nature female with a massive size advantage to even make it a fight.