The only asset that would improve the chances of landing jabs on a southpaw is greesy lighting speed, I mean your jab has to be faster than the blink of an eye, plain and simple it has to land before the opponent can react, they way I trow my jab is I think of it as a whip nice and loose and I whip it out there, loose than you tighten at the last microsecond, like ANDRE BERTO or use a distraction step on his foot, shake your other hand like JEFF CHANDLER, keep your jab hand a little extended so it doesn't have to travel far, look at his eyes if he so much as glances in another direction .....POW