Ali was the complete package: offense, defense, everything. He fought the best fighters from several generations in a long career. Tyson had a super short "prime" in a very weak era. As soon as competition got better, he was exposed. For the record, Ali took a long break from boxing, too (even longer than Tyson's). But he came back, past his physical prime, and became champ during the true golden era of HW boxing. There's no comparison between them. Your little "pressure fighter" analysis sounds like a 2nd-grade MMA newbie trying to comprehend something he doesn't understand at all.