Irish Bob would be lucky to take a razor close decision in this one..he would be forced to be boxer in this case and would find out not to engage in any slugging contests with Johnson..Murph didn't have the power to spark Marvin like so many who conquered him..a rematch would probably see the reverse..a Johnson win, maybe by a bloody tko.
I actually see Marvin busting up Bob with the fast pace enough early to score a 6th round knockout but actually more likely I think Murphy weathers the store and lands his own shots enough to eventually dictate the pace when Marvin tires, then opening the door for a later rounds knockout.