Calzaghe won the 168 World Title in 1997.
Roy was at 168 in 1996 (then lost the next year at light-heavy with that despicable cheap shot KO of Montell Griffin, hitting him when he was down.)
Roy wasn't a big light-Heavy. And Calzaghe was no volume puncher back then; he knocked peoples' brains out back then until his hands went bad on him, and he was forced to change up his game. They should've fought in '98 or 99.
Instead, roy waits 10 years and Calzaghe completely clowned him.

The Champ calls the shots, not the contender, and Dariusz Michalczewski was the undefeated lineal Champ.
A contender doesn't dictate terms to the Champ, and contender Roy wasn't never even a big draw either by the way. Time and time again, Roy said he wasn't going to Germany. I know I've seen plenty of german fighters go to the states and get completely ripped off in America (Schultz/Foreman, Sturm/De La Hoya, Schmeling/Jim Braddock, Abraham/Dirrell,)

Hopkins will go down as being a much better fighter than Roy Jones.
When they fought in '93, Hopkins was still a bit green; he was a late bloomer and didn't put it all together till he was 30 years old in 1995. Then began the Hopkins domination of Middleweight, and Roy never wanted any more part of him. Roy denied him the rematch for 17 years until Roy needed the money.

Same for Toney. Roy struck when the opportunity was there, and knew he wasn't getting toney at his best at 168 because Toney was outgrowing the division in '94, and you know what? Roy didn't want to fight toney at his best.
Roy could've done that lucrative rematch in 1995, '96, '97 as they were in the same class, but Roy wouldn't do it again at light-Heavy because he knew Toney wouldn't be weight-drained.

Gerald McClellan. Roy says he wouldn't take that fight because they were friends. Bull$#!t. Fighters fight and want the opportunity, the money, the notoriety that they are The Man. Roy knew that this man was one of the most dangerous men in boxing and wanted no part of him. McClellan was at 168 in 1995 when his career ended. They were both middleweight title holders at the same time in '93 and '94, and both went up to super-Middle the same time too. Roy didn't want that fight.

Julian Jackson was still a very dangerous fighter in 1993, 94, and had only lost his Middleweight title to McClellan in '93, the same year that Roy won a Middleweight title.
Roy never wanted to step in with a 1-shot artist like Jackson.

It's because roy's weakness all along was his chin. When Roy got knocked out in the gym as an amateur, they hushed it up, but Sugar Ray Leonard was into promoting at the time and was there. It's why when Roy went pro, Sugar Ray wasn't going after Jones too hard the way the other promoters were; Ray figured the kid'll get caught before too long and would Roy be worth the investment seeing as Ray had the inside track.

The Dark Destroyer destroyed Gerald McClellan in 1995 at 168. Roy had a Title right then at 168. He didn't want what happened to McClellan to happen to him.

It's why Roy avoided the most dangerous guys.

Roy avoided these elite guys above and fought 2nd tiers instead like:
ricky frazier
antoine byrd
Vinnie Pazienza
eric lucas
tony thornton
merqui sosa
lou del valle
otis grant
reggie johnson
david telesco
richard hall