Way back when, late 60's-early 70's, I raced stock cars. I was claimed to have an acute talent for judging just the instant when the starter would throw the green flag and was more often than not the first car to 'jump' at the rolling start used in circle track racing. Now that's not the same as 'jumping the gun' which is usually illegal, just evidence of really fast reflexes. Most of my competitors started calling me "jumpinjoe" around the pit areas.
As an aside, my dad was a founding member of NASCAR and did run a very short career in that sanctioning series. But when he raced (late 40's-early 50's) at some of the same small tracks I later raced around the southeast, he also had the same talent ................. and the same 'nickname'.
"Like father/like son"? I don't know, but I like thinking it's so.