How Sports Betting Odds Work

Widespread legalization of sports betting has brought a lot of new bettors to the table. The opportunity to have some vested financial interest in sporting events that you are going to watch anyway is a pretty attractive proposition. As a result, a lot of novice gamblers have signed up to try their hands at betting on sports.

There is a process to learning how to bet on sports. Admittedly, a lot of people, many of us included here at ATS, have gone bust a time or two while getting a feel for how everything works. The best way to set yourself up for success is to take the time to learn the basics and to understand how everything works. Once you get that part down, then you can handicap and break down games like you’ve probably been doing with friends or for fantasy leagues in the past.

Understanding how sports betting odds work is a big step in that process. Many people look at the odds board in a retail sportsbook or at the odds on a website or mobile app and just see numbers. There are some things that you need to know about how odds work in sports betting and about some of the terms associated with them.

How Sports Betting Odds Work With The Point Spread

Arizona Cardinals +1.5 (-110)

NY Giants -1.5 (-110)

This is a point spread from the NFL Games of the Year at DraftKings Sportsbook New Jersey, which includes all of the lines for Week 1 of the 2020 NFL season.

How do the sports betting odds work for this game? The Giants are -1.5, which means that the Giants are favored by 1.5 points over the Cardinals. If you bet the Giants at -1.5, you would need New York to win by 2 or more points before 1.5 points will be subtracted from their final score.

The Cardinals are +1.5, which means that 1.5 points are added to their final score. If the Cardinals would win the game by adding +1.5 points to their total number of points, then the Cardinals win the bet.

Let’s say that this game ends New York Giants 27, Arizona Cardinals 24. If we subtract 1.5 points from the Giants, they still “win” the game by a score of 25.5 to 24. If we add 1.5 points to the Cardinals, the Giants still “win” the game by a score of 27 to 25.5. In sports betting terms, we would say that the Giants “covered” the spread.

The -110 in this point spread is called the vig, which is short for vigorish. Some people also call -110 the “juice”. The vig is for the house and we have a much more detailed explanation on what the vig is on our “What Does -110 Mean for a Sportsbook?” page.

For your purposes as somebody just starting out, think about the vig as a tax or a commission. Instead of getting back even money on your bet, you get back about 90.9% of your bet. It is one of many ways in which the sportsbooks attempt to make a profit called a “hold” on a game. Some people will Bet to Win, which, in the case of -110, would typically mean something like $110 to win $100 to have a nice, round number. Others will Bet to Risk, which means betting any amount that they want to win roughly 90.9% of that amount. We have a more detailed explanation of Bet to Win vs. Bet to Risk as well.

How Totals Odds Work In Sports Betting

Cardinals/Giants Over 47.5 (-110)

Cardinals/Giants Under 47.5 (-110)

In our above example between the Cardinals and the Giants, let’s say that the total, also known as the Over/Under, is 47.5. This is a very simple and straightforward wager. If you bet over 47.5, you are betting that the combined point total between the two teams is higher than 47.5. If you bet under 47.5, you are betting that the combined point total between the two teams is lower than 47.5.

The Giants scored 27 points and the Cardinals scored 24 points. Because 51 is higher than 47.5, the game went “over the total”. As you can see, the vig still applies to this type of bet as well.

How To Read Sports Betting Odds – The Money Line 

Arizona Cardinals +100

NY Giants -120

Money line betting simply means picking the winner in a game. In a game with a low line like 1.5, the money line odds are going to be pretty close to the regular -110 vig. In this case, the Arizona Cardinals are +100 to win the game, which is also known as even money. If you bet $100 on the Cardinals to win and they won the game, your bet would win $100.

If you bet on the Giants at -120, that is a higher vig than -110, so your payout would be more like 83.33% of what you bet instead of 90.9%. If you bet $100 on the Giants to win and they won the game, you would win $83.33.

Using the above example, the Giants were the winners, so the -120 side would win and your Win Amount would be relative to the amount that you bet on the game. If you bet $120 to win $100, you would win that amount. If you bet $200, you would win $166.67.

How Sportsbooks Use Sports Betting Odds

Oddsmakers post a line. Bettors wager into that line. Based on the bets that come in, sportsbooks often move the odds. Remember that the vig exists so that sportsbooks can attempt to balance their exposure and risk in order to make a profit on the game no matter which side wins.

They can do that by moving the vig itself. If a line is -110 on both sides, but more bets are coming in on one side than the other, the vig could move to -115 on that side. If the vig moves on one side, it will move on the other side as well. A move to -115 on one side means a corresponding move to -105 on the other side. The lower vig amount is designed to entice betting action on that side of a game.

Sportsbooks can also outright move the odds on the game. A total of 47.5 that has received a lot of betting action on the over could be moved up to 48 or 48.5. That is done by the bookmakers in hopes of getting bets to come in on the other side at a more attractive line for bettors. In this case, that would mean the bettors that want to bet under 48.5. They may not have felt comfortable betting at 47.5, but feel better about 48.5.

As the point spread moves, the money line moves in a corresponding way as well. Let’s say that a lot of money comes in on the Giants at -1.5. The line moves up to -2 and the money line may move to -130. Money keeps coming in on the Giants and the line moves up to -2.5. The money line may move to -140.

Bookmakers and risk managers will keep moving the odds if necessary until they begin to see betting activity come in on the other side. Remember, the goal of the sportsbook is to try and have as even of a split as possible on both sides of a game.

Think about the vig at -110. Let’s say that bettors from both sides are betting $110 to win $100. If 50 people bet $110 to win $100 on the Cardinals +1.5, there is $5,500 worth of wagers on that side. If 50 people bet $110 to win $100 on the Giants -1.5, there is $5,500 worth of wagers on that side.

Because the winning amount is only $100 on each $110 bet, the sportsbook would pay out $5,000 worth of winnings and “hold” the $5,500 worth of bets on the losing side. Therefore, if the bet counts were exactly even on the game, the sportsbook would “win” $500 for itself on that game.

If that count gets too heavy to one side, the sportsbook becomes exposed. If there are 50 bets at $110 on the Cardinals at +1.5, but 100 bets on the Giants at $110 on the Giants at -1.5, a Giants win would be very bad for the sportsbook, who would pay out more in winnings than they held in losses. As a result, they will move the lines or sometimes increase the vig in hopes of balancing things out.

The process is certainly more detailed for the sportsbooks than that, but that gives you a good overview into how sports betting odds work for the player and how odds work in sports betting for the sportsbooks themselves.