A completely unorthodox but unique style, in his prime Roy Jones Jr. was untouchable, his incredible speed made up for his lack of technique, but after he lost that he was exposed...
I don't think his technique ( at least offensively) was bad. His offensive techniques were excellent. He was very smart. Its just that his defense was overly reliant on reflexes. Peak RJJ is close to an unbeatable fighter. The most dominant fighter i have seen at his peak.
Prime Roy seemed like he would have been a nightmare to deal with. How would you find sparring partners who could even come close to mimicking what he did in the ring? Even Hopkins & Toney had trouble getting a glove on the guy. FWIW, he probably could have extended his prime a bit if he went to Cruiser after Ruiz, rather than trying to squeeze back down to LH. He was a rock solid 193 for Ruiz. Getting back down to 175 at that stage of his career had to take a lot out of him. He clearly wasn't the same after that.
He was pretty special. It's easy to forget how dominant he was. I remember being told he lost to Tarver and being completely shocked.
I'd say he had his own effective technique rather than saying it was a bad technique. Boxing can be a very creative art in this aspect.
RJJ was just a one of a kind fighter who couldn’t be imitated. A very gifted and unique specimen unlike any other with that combination of speed, power, and reflex. A dominant and near unthouchable apex predator in his prime.
I always saw RJJ's technique as more of a "freestyle" approach. His technique was wrong on many levels but made up for it with his boxing instincts and ring IQ that was heavily supported with his supreme physical gifts. He had creative offense, great use of angles, and a very unorthodox style that made him unpredictable. Despite his obvious fundamental flaws in his game that's what made him a special fighter. RJJ wouldn't be RJJ if he fought in a very methodical, by the book style.
In his prime, Roy was close to unbeatable. Yet Toney and Hopkins aged better. Cause they were more dependent on sound technique than their God given reflexes.