There's probably only Lindell Holmes. Holmes was a good fighter. And Roy sparred with him in the early 90's.
This is a great post. I really enjoyed reading it. As a huge fan of Roy's, I don't think that you can just look at their abilities and their records and then predict an easy win. Like you have noted, experience is absolutely vital. And then there's the other circumstances which you have mentioned which may have come into play. I think the biggest issue would have been the distance of the fight. Because like you've noted, there's just no way a fighter can replicate that in the gym. So fighting a 12 round title fight when you've never even had an 8 round pro fight before would have been an absolutely huge challenge. And then there's the nervous energy etc, due to the pressure. This is why I respect what you've written so much. As soon as I read the thread, I immediately thought of Lomachenko. As gifted as he is, the transition from amateur to professional is huge. So this would have been a huge task for Roy. However, despite everything that you have written and everything that I've just spoken of, I would honestly still have given Roy a reasonable chance of beating him on a decision. Admittedly, I've not seen too much of Van Horn's career. I've only seen a few fights. But although he legitimately won a JMW title, he was a career B-C level fighter who only held the JMW title for a very brief period. He won the title against a fellow career B-C level guy, before losing it immediately afterwards. So he was never a seasoned world champion who was a genuine world class, top level fighter. And had he have found himself in a stronger era, the likelihood is, he'd never have been good enough to have won a title and then had a prolonged run as a world champion. The biggest win of his entire career was against Lindell Holmes up at SMW. And Lindell Holmes was a good fighter. So that was a very good win. But at JMW, he only beat guys of a low level, similar to the level that Roy fought at during his first 2 years as a pro. There's a lot of 'ifs' in my thought process. But I think that if Big Roy had have been extremely confident and Roy could have kept his composure and paced himself, then he would definitely have had a very reasonable chance of getting the win. Good debate.