In sports betting, an oddsmaker's job is to calculate the odds, or probability, of one side winning against the other. The odds are presented showing a favorite and an underdog, a point spread or moneyline, and a total, each of which is used to make various types of wagers.

In football and basketball, a point spread - also called "the line" or "the spread" - is used to level the playing field between two teams for betting purposes, and is designed by the oddsmakers to draw even money on both sides of the game. The oddsmaker predicts that the favored team will win by a certain number of points.

• The favorite is always indicated by a minus sign (e.g. -5.5) and the underdog by a positive number (e.g. 5.5).
• If you bet on the favorite, you win your bet if the favorite wins AND their margin of victory is greater than the point spread.
• If you bet on the underdog, you win if the underdog wins, ties, or if the favored team wins but fails to exceed the point spread.
• If the favorite wins the match by exactly the amount of the spread, the result is declared a push and money is neither won nor lost (the wager will be returned). Spreads are often given as something-and-a-half (35.5, 10½ , etc.) so that the result will necessarily fall above or below the spread, thus avoiding a push.
• Example: Imagine that the Tampa Bay Buccaneers are 7-point favorites against the Atlanta Falcons. The final score is Tampa Bay 18, Atlanta 13. In this case the favorite, Tampa Bay, won "straight up" against the underdogs, since they beat Atlanta… but they did not win against the spread (ATS), because they won by fewer than 7 points. If you bet on Tampa Bay, you lost your wager; if you bet on Atlanta, you won.
• It is standard for point spread bets in most sports that you wager $110 to win $100.

A moneyline, used in baseball and hockey, takes the place of a point spread. In moneyline betting the team wagered on has to win the game outright, regardless of the score. There is no spread to cover, and the oddsmaker evens out the action by adjusting the price on both the favorite and the underdog.

• The minus sign (e.g.-130) always indicates the favorite and the amount you must bet to win $100.
• The positive number (e.g. 120) always indicates the underdog and the amount you win for every $100 bet.
• Using these numbers as an example, therefore, you would bet $130 to win $100 on the favorite, while for the underdog you would bet $100 to win $120.

The total, or over/under (O/U or o/u), is the number of points oddsmakers expect will be the total score for the contest (both teams combined, overtime included). It doesn't matter who wins or loses.

• You bet on whether the total points scored will be over or under the predicted number.
• Using as an example our Bucs-Falcons game, imagine that the predicted total for the game is 29.5. The final score of Tampa Bay 18, Atlanta 13 gives a result of 31. If you bet on the over in this game, you are a winner.
• If the total score is exactly the same as the predicted total, the result is declared a push and money is neither won nor lost (the wager will be returned).
• As with point spread bets, you must generally wager $110 to win $100.

Betting on a point spread or money line is sometimes called betting "sides" - that is, betting that one side or the other will be the winner - while betting the over/under is referred to as betting "totals".