Well i have never really had trouble with the jab i go to the head and the body with it and get alot of snap on it i use to set up shots i use it as range finder also so i can set up my straight right hand.

I also counter jabs with my right glove bit like Tim Witherspoon with right arm crossed over to his chin i don't quite have that defence but i do block with my right glove and then counter with left jab of own a similar way to how Witherspoon done it to Holmes.