Make a list of fighters who have achieved successes greater than their potential and beyond all expectations.
Carl Froch, heck of an overachiever, I'd heard him say that his style was inspired by Naseem Hamed, I can't think of a more unsuitable fighter. Stellar resume, hot wife, supposedly had a growth spurt from 5'3" to 6' after 17 and last but not the least knocked out Groves in front of 80000 fans at Wembley. That's like getting every gift on the wish list.
Chris Eubank snr Herbie Hide Frank Bruno Lloyd Honeyghan Nigel Benn All pretty good, probably over achieved. Credit to them all.
Eubank and Benn didn't overachieve, they were both super tough and belonged at the level they competed at. Would they have lost to RJJ? Yes Would they have been among the best wins on RJJ's resume? Yes Would they have had a chance (note I said chance) against Toney and BHop? Yes
Wladimir Klitschko If you look at what he achieved after the Lamon Brewster loss when everyone had written him off. Then going undefeated for 10 years as HW champion. Simply amazing.
Another one that comes to mind is Steve Collins , scalped both Eubank and Benn twice at the tail end of his career and earned a lot of respect. I saw him lose to Mccallum , boxrec say he lost to Reggie Johnson and Kalambay too but I haven't watched those fights. Tough nut, not the most technical guy out there, in fact the way he was lunging in his fight with Eubank would give you second hand embarrassment but it is what it is.
Ricky Burns. Big fan of Burns so don't mean it in a disrespectful way, but I'd say he achieved more than expected of his talent. His dedication, professionalism, heart and toughness more than made up for any shortcomings in his ability.
Micky Ward and Arturo Gatti. Seems to me Gatti had a little more boxing talent but both got rich and famous and fought some HoFers based on their toughness and the appeal of their styles.