Betting against the spread means placing a wager on a sports event where one team is given a point spread advantage and the other team is given a point spread disadvantage. For example, if the point spread for a football game is -7 for the favorite team, betting against the spread means placing a wager on the underdog team to either win the game outright or lose by less than 7 points. This type of betting is popular because it levels the playing field between the teams and offers more options for bettors.