Before anyone says this is a stupid question you have to remember there has been some poor fighters to pick up belts.
Bent was good enough to destroy Morrison, so... Anyway, Bruce Seldon comes to mind, and maybe some of the real early guys like Sullivan, Corbett, Fitzsimmons, Hart and Burns. I will exclude even Jefferies, who I think would have won.
Did Bentt win or did Morrison lose? IIRC there was a lot of parties and other assorted nonsense during Morrison’s camp because his next fight was going to be against Lennox Lewis with a huge payday.
Tommy Burns and Marvin Hart, definitely. You know it was a threadbare era for the Heavyweight division when someone as extremely limited as Marvin Hart became the Lineal Heavyweight Champion, post-Jeffries. Also, Burns was 5 foot 7 and weighed in the region of 175Ibs, so Allen would've mauled him.
