A bench jockey
is a slang term in American baseball
to describe a player, coach or manager with the talent of annoying and distracting opposition players and umpires from his team's dugout with verbal repartee. The verbal jousting is frequently called "riding" - hence the "rider" from the dugout becomes a "bench jockey." The art of riding opposition players enough to unnerve them (but not enough to enrage them and provoke a fight) is believed to be fast-fading in the 21st century game.