Buster Douglas gave the whole world the blue print on Tyson....snapping jab, and tie him up on the inside(ofcourse you need good stamina and chin and not be crapping your pants)...Considering Ali has arguably the best hand speed ever in the HW div, great foot speed, very hard to hit, great stamina, and a awesome chin I don't see how anyone can say tyson wins. Now onto Lewis....Ali would lay back much like he did against Foreman and force Lewis to carry the fight to him then counter and pepper lewis winning with a late round KO..Ali would probably give away the first rounds but his hand speed, slipperyness and great footspeed would start fustrate Lewis and close his eyes up....The only fighters I give a legit chance to beat Ali is Joe Louis and Jack Johnson...in their respective primes that is.