I do not think we will ever get a definitive answer. Back in 1988 I was one of them who: A: Considered Spinks the champ and B: Thought he would win. I was far from alone. I understood Tyson was favourite, and could see a way he could win, but I did not consider this was anything but a very tough fight for Mike, and it was not going to be one of his blowouts...
Tyson was the best finisher in heavyweight history, Spinks didn`t have the reach to spoil and jab the way other Tyson opponents did, I don`t any fighter Spinks size would stand a chance v Mike.
Tubbs wasn`t scored, he won the first round the fight then went toe to toe in the second, he`s the only fighter Mike fought that could match his hand speed.
Qawi was far smaller than Tyson, Holmes far older in `85-`86 and Cooney was nowhere near Tyson`s level, I don`t think Cooney was that high in the ring mag ratings when Spinks beat him, how the hell was that proof he stood a chance v Tyson?
I'll start answering your question with a question, Mark. Were you around at the time, watching boxing? Because, as they say, hindsight is 20/20. Assuming you were, let's take it point by point: "Qawi was far smaller than Tyson." Definitely. Spinks '83 was smaller, weight-wise, than Spinks '88. But '83 Qawi was steamrolling everyone. I thought he was going to chop Spinks in half. But Michael found a way to win. "Holmes was far older in '85-'86." Correct there, too. But up until September 1985, he'd always found a way to win. We knew he was on the downside. But the Spinks bout was a gimmick easy defense. Yeah, Holmes was no Tyson at this stage. Holmes was no Holmes. But he was still the undefeated heavyweight champion, ATG Larry Holmes. And Spinks found a way to win, twice (albeit disputably in fight #2). "Cooney wasn't high in the ratings." He wasn't, but he was high in training (ha ha). 'Course we didn't know that. In 1987, Cooney was a big bruiser with a decent jab, massive left hook, and even a decent right hand. He'd only lost one fight. Since Holmes, he'd seemingly got his head together and taken out the undefeated Phil Brown, old warrior George Chaplin (who'd never been taken out that early), and young fringe contender Eddie Gregg (who'd also never been taken out as early or as easily). And Spinks destroys Cooney. In hindsight this isn't a big deal, but at the time it was pretty impressive. Michael Spinks was an undefeated heavyweight champion, first light-heavyweight champion to win the heavyweight title, and had been resourceful and inventive in getting where he was at that point. Additionally, there were already rumblings that Tyson was about to implode, that a Buster Douglas was around the corner. Of course Spinks had a chance. But not in hindsight.
IMHO, both. In those respects it was the same with Liston and Patterson, but with different stylistic factors at play.