BoxRec

I don't think Marvin faced many with greater power than Roy Jones, who was a serious banger at MW. What's for sure is that Marvin is more than solid enough to take Jones' punches and then some. Jones was also a serious speedster, he may be fast enough to box, keep away and nick a decision. The best yardstick is Jones' points win over a fairly inexperienced Hopkins, and the odds are that Marvin would do much better and grind Jones down via mid-late rounds stoppage.

I'm not saying that Jones would have seriously hurt or stopped Hagler, but he clearly had enough power that Hagler wouldn't be able to walk through his punches as "speedy pot shotting" would imply.