Bowe, decison of course. He'd have to dig a little himself , but at the end he'd win the rounds by being busier. And Mercer is a catcher in there anyway. Mercer might have a few good moments in the bout but I sure don't see him being a big enough opportunist to get a ko when that brief window might be open. The other factor would be the toll it takes on Bowe to win this. He sure didn't hold up well in that department and this is the type of fight that causes erosion in fighters, win or lose. Mercer is much much better in that department but that advantage won't win him this fight.
It would be a tougher fight than most would probably predict. In the end I'd pick Bowe by decision or perhaps even late stoppage. But he's not going to box Ray from the outside the way that Larry Holmes did, as Riddick's game was mostly about infighting. This would give Mercer a chance to work both the body and head while landing some big shots and taking some serious blows in return. Both guys get rocked heavily in this one and both end up with swollen faces. My reason for picking Bowe was because he had the better inside fighting game of the two, a chin that could take Mercer's best and was the superior in size. Power wise I might rate as being close to equal.
Bowe would riddle Mercer with every punch in the book. Bowe would love fighting a guy like Mercer who would come forward on him all night.
The motivated, fit Mercer would be a stern test for Bowe; the lazy, fat, unmotivated Mercer would be a cakewalk. Mercer impressed me with how he out jabbed Lewis in their fight; and he showed that he could take big punches from a big, strong heavyweight and keep coming. Bowe has more natural boxing ability, but Mercer brings plenty to the table.
Sorry the best Mercer beats Bowe!!! this fight would be a war of attrition, fortitude, and balls, and in a long tough brutal slugfest i think Ray would dig a little deeper and win a clear cut decision.