That's no brainer---the average heavyweight would put the best flyweight boxer in history to sleep with the first meaningful punch that he could land. The best flyweight may be able to land more punches, including his strongest KO blow but they would just bounce off the big guy.

Come on are you kidding, the heavyweight would destroy the greatest flyweight of all time every time, my 2 year old boy knows this much

Heavyweights tend to be slow and clumsy. If the flyweight was good technically, he could use his boxing smarts to beat him. Just look at the hate/valuev fight. Valuev was nearly a foot taller than haye, but was simply outclassed on the night

Considering the size disparity, the average heavyweight would win. I mean, all the big guy has to do is stick the smaller man and spank him, lol.

the Heavyweight will estroy the fly

The best flyweight boxer in the history of boxing or an average heavyweight boxer that weighs 230 or 240lbs? Would the heavyweight be able to win just because of size? Or does skill matter more?