While Kessler was clearly better overall, and even faded he was, I think Dirrell matches up very well with him. Would probably end up being a close decision that Dirrell deserves. Tough to say, really.
Dirrell would have been very tricky, but Kessler connects and that little worm finds the quickest out
Assuming the fight was in the USA, Dirrell would have had an easier time beating Kessler than he did with Froch. If the fight was in Denmark, Kessler would win by UD after suffering 3 knock downs in 3 different rounds.
direll youd imagine would win the exhanges for most of the night, kessler would keep plugging away with his solid style that could find gaps to hurt direll and if he did he could finish him