Depends on which Mercer shows up. Disinterested Ray plods around and gets outpointed . Mean Ray takes AJ s head off in about 7 rnds .
Mercer was a bad dude with power and an iron chin but inconsistent. Joshua could win by decision but I wouldn't rule out Mercer by devastating KO.
Most likely Joshua. Mercer was a very tough guy but his power is overrated and he lacked in certain fundamentals
Mercer did have a jab on occasion, but Joshua's boxing skill is a clean advantage. On the other hand Mercer's chin compared to Joshua's is also a clear advantage. Joshua appears to be the favorite and maybe so but I'd bet on Mercer