Over–under

An over–under or over/under (O/U) bet is a wager in which a sportsbook will predict a number for a statistic in a given game and bettors wager that the actual number in the game will be either higher or lower than that number. One of the most commonly used statistics is the combined total score of the two teams, and for this reason the wager is also known as the total.

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 wager that the combined score of the two teams would be either more than or less than that number. Since the combined score of that game was 45, anyone who had bet on "under" won. The bet is called a push if the actual number exactly equals the over-under, in which case all bets are refunded.

Dice

A variant of over-under betting, known as Under Over, is a dice game played at various festivals. The object of the game is to predict whether the dice will roll to a total of under 7, over 7, or at 7. The game is typically played with 2 dice.

A player typically places a wager on one of three spaces. These spaces are:

• Under 7 (usually pays 1–1)
• Over 7 (usually pays 1–1)
• 7 (usually pays 4–1)

For instance, if one bets one dollar on under and the dealer rolls under, they gain a dollar as well as get their dollar back. If the dealer rolls a seven and one bets on it, they make four dollars. Once all the bets have been placed the attendant closes the betting board with a screen and then puts the dice through the chute. Players then get paid accordingly.

One variation of Under Over involves foam dice, two of which are thrown in the middle of the players; in another variation, two balls are thrown into a giant wheel consisting of twelve spaces of numbers ranging from 1–6. No wire fence is used to block the bets in that case.

Initial cost

The goal of the betting company is to get the same amount of bets on both sides of the overtime game. In theory, this means that the manager can set a zero value and adjust it later based on the number of incoming bets and/or factors that may affect the outcome of the game. In practice, the initial value is based on both quantitative indicators (e.g., loss records, average points per game, etc.) and unofficial information (e.g., press reports, player injuries, etc.). To get reliable information about a team's scoring potential you have to look beyond that and take a long term view.​

Statistics

As a rule, the total is the sum of the total points of both teams for the game. However, there are bets on a different type of total, such as the total number of points scored by only one team and the total number of points scored in the first half by both teams. Many other statistics can be used, such as:

• In American soccer, the total number of yards or attempts by a player or team, down conversions (first or third down), interceptions, completions, completion passes, percentage of throws from a play, etc;
• In basketball, the total number of assists, steals, turnovers, turnovers, steals, etc;
• In baseball, the total number of home runs (home runs), RBIs, etc.