When I think of Marvin Hagler I think of a professional guy. He took the best punch Tommy Hearns had to offer and wobbled but stayed up. Unbelievable chin and desire. Jones would not have knocked out Marvin, and to win a decision. no way down the stretch. Strategy was needed more than anything, and Jones was fast but would have been worn out by Marvin's jab and just relentlessness. Someone mentioned if Ray could do it Roy could. Ray studied Marvin for years and watched him as commentator on HBO.. For 6 years he thought about fighting Marvin and saw his buddies like Hearns and Duran fight Marvin. And he knew Hearns and Duran better than anyone and gauged Hagler from those fights. He knew what to do with Hagler and what not to. Ray also had a style to beat Marvin most guys did not. He fought lateral and moved lateral the whole time and most guys cannot more laterally like that the whole fight like Ray. He did not stay on the ropes, He hit and then moved. He just timed Marvin well. Talk about studying a guy. Roy reacted more in fighting but I do not think he looked for weaknesses like Ray. My pick is Marvin to stop Roy in 10 rounds in a good fight for Roy for a few rounds of boxing but a boring start, and then Marvin slowly getting to him and Roy spending too much time on the ropes. This is not all those other opponents of Roy like Gonzales who fought Roy and couldn't do much when Roy leaned on the ropes, this is Marvin Hagler.