As a note, remember when everyone thought Gene Fullmer had no jab, but he pulled it out to outbox the very tough Cuban Florentino Fernandez in a MW SD title defense.
Mosely had a jab. Look at his 135 fights, even at 147 vs Taylor and Stone he was jabbing with real conviction. But as he fought bigger stronger guys like Forrest, Margarito and Winky who could not be moved as easily he did paw a lot with it and tended to use it as a set up for a whipping right hook. Late in his career vs Vargas, Cotto and FMR he had really slowed down. That jab was more of a flick and nothing with authority. Shane came to our gym some months after the Margarito fight. He sparred a whole bunch of our amateur and pro fighters. About 6 guys in total , 1 round each one after the other. He totally schooled every one, just using his jab he never once opened up at all. He was moving his head off the center line and sticking guys with a quick jab but would move around and confuse them rather than punishing anyone. He was so damn relaxed it was awesome to watch, just like a stroll in the park for him.
Lamount Peterson - In most of his fights he goes for long stretches completely abandoning a jab, just marching forward behind a high guard seems to be Lamount's better idea to close the distance. Danny Garcia - We saw vs Matthysse he has an educated jab, but his awkward style and slow fight pace means he can use heavy lead body shots or counter left hooks instead. Michael Katsidis - So tough but on the outside he would be constantly countered due to his average handspeed and limited head movement (look at the Marquez, Diaz and first Graham fight). He abandons all signs of a jab, just smother and throw a chopping downward right hand. I haven't seen anyone throw that strange punch since or before.
I don't know, this is a tough one. I would say poor jabs are different than underutilized jabs. 80s Tyson did use his jab well to set up bigger shots, or even just a heavy jab on its own, out jabbing Tony Tucker who had half a foot on him in height and a foot on him in wingspan. How was Ricky Hatton's jab? I remember him using it against the much lesser opponents, did he use it effectively against the world class fighters he fought? It's been awhile since I seen some of those bouts against the likes of Malgnaggi and Urango, I can't remember if he jabbed much against them. Shorter swarmers are generally going to use them less, but can still have good jabs. I'm sure there were some that had not-so-good ones.
It's Ingemar Johansson. It was a poor, pesky light powderpuff of a jab. But it was an effective step off jab. Purely to blind an opponent momentarily to change direction.
Cotto was able to throw heavy, well timed jabs but while I could be mistaken, I don’t recall him being very successful with his jab against his best opponents.