DJ had excellent technique, RJJ probably had excellent technique too with his amateur background, but he chose to use his physical talent more. DJ is one of those fighters I like to watch, old school (50s-60s) NYC trained, but not as quick or strong as RJJ. This would be an interesting fight, fun to watch, but RJJ probably pulls it out with speed. Probably a lot of close rounds and unlikely that either gets caught with anything big by the other.
I agree, that as Pat M says, Doug Jones was old-school, well trained. By this I mean he was an aggressive boxer/puncher who knew how to gradually ratchet up pressure as a fight wore on. I think he was at his best before the Ali fight, which is the time period in his career which I assume that this thread is considering. I think he would wear down and discourage Roy Jones if the fight was set for the old-school 15-round title distance. The longer the fight was scheduled the better DJ's chances. In a ten-rounder, I think he would be coming on strong at the end of the fight, maybe winning a decision, maybe not. It would depend on how much he could slow RJ down. For reference I refer to DJ's pre-Ali fights against Zora Folley (No. 2), Bobo Olson, Pete Rademacher, and Bob Foster.
The guy who reffed the fight with Jones Clay...forget...I either read or saw old footage of him, saying he felt Clay won, but he had to dig deep. DEEP. The way he described it was that Clay was being forged in the fire for greatness and as a result that fight convinced him of being one of the few that felt Cassius could in fact beat Sonny Liston. Against Jones Jr, I think the same. What would've been the difference is that Dundee had no desire to TRY to teach Clay to go to the body. RJJ would. And if we're talking RJJ that fought McCallum? That was when he prefaced a body attack. The kind of attack that cracked that Hill rib! RJJ doesn't pull straight back like Clay did either, nevertheless, I can still see RJJ having a difficult 1st 1/2 of the fight by incessant pressure, then adjusting his attack. What takes him 1/2 the fight is by foolishly leaning on the ropes as RJJ's worst habit IMO. Doug digs into those ribs and has a GlenCoffe workman like workrate that forces Roy off the ropes. His power would've been more effective than Glencoffe's. RJJ is questioned on how good is he really because of how difficult the win is. Like with Clay, RJJ is placed in the fire showing how deep he can dig down to win.