Marcus lived about 3 blocks from me when I was in Russellville AR. Not the gretest boxer in history, but as a "professional opponent" he's faced a who's-who of boxing big names.
Among the guys he faced you may have heard of (yes, he lost to all):
I asked him who was the hardest puncher he fought, he answered without hesitation, didn't even have to think about if for a second.
Take a few guesses, I'll let you know if you pick the guy, if not I'll disclose a little later.