Nobody has been as effective with the duck and weave as Tyson? Have you watched Ali's fights? Muhammad Ali was the most graceful heavyweight boxer of all time. That man could literally float like a butterfly - that wasn't hyperbole. He was graceful and fluid, and his ability to let haymakers and combos slip past him was unparalleled:
The greatest fight of all time would be Muhammad Ali in his prime vs. Mike Tyson in his prime. Either, if they landed 'the shot,' could level the other. Both could dodge punches like crazy. Ali had that length and leverage, Tyson had the compact power. It would be an absolutely great fight. Legendary.
If I had to pick a winner between the two in their prime, I'd take Tyson, but just barely. Ali would definitely have a shot to win - WAY more than a "puncher's chance" - but I gotta believe that late in that fight, after slowing Ali's feet just enough with body work, Tyson would be able to land that one devastating, crushing shot that he was so famous for. Ali may be able to withstand that punch (the man could take a punch better than Rocky), but he wouldn't be the same after.