I actually think that Tyson would have had a really good chance of winning UFC 1. He's stocky and looks like he'd be hard to take down. If you think Tyson hits hard with 12 oz. boxing gloves I'd love to see the damage he'd do with no gloves.

Gracie's hardest win before retiring from the UFC was against Kimo, simply because of his strenth, and the only reason he won is because of all the hair pulling he did. Another what if situation, but damn wouldn't it be fun to watch.