I'll throw my hat in the ring for Botha. He was a big, tough guy with a decent punch. He was beating Tyson up to the point of the stoppage. I think he loses the early rounds but takes over mid fight and takes it on points. Edit: now that I actually look at Leon's record, I'm pretty sure Botha takes care of business. He lost to way worse guys than Francois.
Can't judge everything by record. Aside from already suffering from CTE in the early 80's, Leon's drug and alcohol problems were out of control by 82' and he should not have been fighting soon after. Remember, this is a guy that had hundreds of wars in the amauters and was already pretty shop worn early on in his pro career. The booze and coke didn't help at all. If we are taking both guys at there best, no way Botha could deal with volume coming his way. Yes, Botha's was a much bigger guy but the Gold medal winning Leon was a much better fighter.
Sure I agree that Spinks had a good volume when he was younger. If he manages to stay out the way of the incoming for the duration he'd win wide. But the flipside is that Spinks was a small dude for the heavies. I'm not sure that he can take a heavyweight punch very well, nor am I sure that he'd stick and move al night long. Against Coetzee, for whatever reason, he had the idea that he'd blow him away fast. Now we all know what happened there. The very fact that he tried to go to war with a bigger and harder hitting man tells me that Leon Spinks was not very wise when it came to fight strategies.
Yeah it's always tough to grade Spinks chin. He was so wildly inconsistent. Coetzee caught and got him out yet Spinks was able to stand in against Mercardo who was a brutal puncher that had just starched Berbick and Shavers. He is without question the most inconsistent fighter to ever win the leniel title.
Can see Spinks throwing himself at Botha, lookin good for a while then Leon getting belted on the inside. Botha stops him in 8.
To be honest a lot of those losses in the 80's and 90's were when he was a full blown alcoholic and drug addict.