An over-under or over/under bet is any kind of wager made in which a sportsbook will predict a number for a statistic in a given game (usually the combined score of the two teams), and then bettors will either bet that the actual number in the game will be either higher or lower than that number. For example, in Super Bowl XXXIX, most Las Vegas casinos set the over-under for the score of the game at 46.0. A bettor could bet that the combined score of the two teams would be either over or under that number (as it happened, the combined score was 45, so a person that had bet the under would have won).

Statistics

Though this bet is most commonly made with the combined score of the two teams, many other statistics can be used, including:

• A team's win-loss record for the season
• In football, a player's or team's total rushing yards or attempts, first down conversions, third down conversions, interceptions, completions, etc.
• In basketball, a player's or team's total assists, blocks, turnovers, steals, field goal percentage, etc.
• In baseball, a player's or team's total number of home runs, RBI, etc.