In sports betting, a back door cover occurs when the team you wagered on covers the spread in the last minutes of the game. Often times this happens when the actual game is a blow out, yet the spread or line of the game is still at play.
The Giants kicked a late field goal to give me a back door cover. They lost by 10, but covered the 12 point spread.
Short for "Bandwagon." The Wagon refers to cheering for a specific sports team, often for sports gambling purposes. Cheering hard for a team can entail, getting more people "on the wagon," steaming the wagon, "throwing coal on the fire," and "pushing the wagon."
Who wants to get on the Steelers wagon with me?
Comon guys! The Dodgers game is tonight. Get on the wagon!