Ive seen Tyson do this, he can get the most hip rotation into his jab and left hook because he has a very square on stance.
Ive seen Pac Man do this too, he will sometimes follow his rear cross or rear overhand hook, with a hip powered "jab"
Also Ive seen other good boxers hip rotation into their jab (one called Yuri? something a chinese russian mixed race boxer that fought in Japan as a lightweight) he did it straight from the more classical more side on stance, without needing to square up his hips first.
Anyway im finding my arm dosnt want to go dead ahead when I try it, rather it badly wants to turn into a hook or a straight punch that goes off to the side.
How are these odd punches done properly?
I appreciate they arnt text book and their effectiveness is debatable but I still want to know how to do them well.