A fork of Rural Dictionary
To try to "up" someone in fraternal verbal competition. Much like a verbal "pissing contest" without the mess. Taken from the literal scoreboard (noun) from a sports match.
Mack: (Drunkenly brags about how many skanks he's been with.) Mike: "Dude, what are we scoreboarding here? Those are nasty hoes. I don't dig that man."