I have my doubts about what Tyson could have done post prison. If you read his autobiography then it's clear that a lot of his post-prison deficiencies in the ring were attributable to his lifestyle outside of it. He was also a mentally weaker man during his return, nothing like the single-minded animal Cus D'amato created. His handlers could have brought him along as slowly as possible and it would not have made a difference. Prison, Alcohol, coke, partying, tail-chasing, lack of commitment to training, age, absence of Cus etc. all made for a diminished version of the phenomenon we knew in the late 80s. And even still, I'm not sure he could have ever beaten Holyfield. But it is an interesting thing to consider: what would a Tyson vs Holyfield fight had looked like if it happened between 89-91?