How Do Betting Odds Work? A Look at How to Read Betting Lines

Sports betting guides from Betsperts

Sports betting is growing in popularity worldwide, and with that growth comes an increase in the number of people looking to cash in on the action. When it comes to understanding sports betting odds, one of the first things you need to understand is how betting lines work.

Here is some sports betting 101: Everything you need to know about how to read betting lines including what they mean, why they move, and why you should shop for them.

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What are Betting Lines?

A betting line is the amount of money you need to wager to win a certain payout. Bookmakers will set various types of betting odds based on the amount of money being staked on an event by the public.

Understanding American betting lines is essential to get in on the action, especially if you’re betting on basketball and football. The first step is looking at how to read sports betting lines.

The + (Plus) and – (Minus) Sign

To understand how odds work, you must know how to tell the underdog from the favorite based on the sign. The favored team will always have a minus sign in front of the odds, while the underdog will have a plus sign. The plus and minus signs on a sportsbook can also indicate fractional odds.

The plus sign indicates that you will receive fractional odds if you win your wager, while negative odds indicate how much you have to wager to win. For example, what do odds of -200 mean? That means you would have to bet $200 to win $100.

Fractional Odds

Fractional odds are the most common type of sports betting line and are found in decimal and moneyline formats. They can be either positive or negative but are always written as a ratio of two numbers.

They indicate how much you need to wager to win a prize. The first number is the amount you will be awarded if you bet the second number, and the second number is the amount you need to stake to win the first number.

For example, fractional betting odds of 3/1 would mean that you would receive $3 in winnings for every $1 you stake.

Decimal Odds

Decimal odds are the second most popular type of line in betting and are used in moneyline and fractional formats. These types of odds are always written as one number with a decimal and can be either positive or negative.

A positive decimal number means you will win the same amount of money you bet, plus your original stake. So if you wager $10 on a team with decimal odds of 2.0, your bet earns $20 total (your $10 bet plus $10 in winnings).

A negative number means you will have to wager more than the amount you want to win. So if you bet $10 on a team with decimal betting odds of -2.0, you would need the team to lose for you to win what your bet is worth.

How to Read Point Spread Bets and Odds

The point spread is the number of points given to the favorite to even out the playing field. The preferred choice is the team that is most likely to emerge victorious, while the underdog is the team that is least likely to win.

The point spread is usually represented as a decimal number, such as 2.5 or 3.5. This means that if you bet on the favorite at they are -2.5 favorites, the team must win by more than 2.5 points for you to win your bet. On the other hand, if you bet on the underdog, they can lose by up to 2.5 points, and you will still win your bet.

Common American betting odds for a point spread are -110. These odds mean you have to bet $110 to win $100. Also, a common term you might see is ATS which is talking about betting against the spread.

A spread bet is very popular because the odds for a favorite are much better than winning the game outright. For example, the Kansas City Chiefs might be -13.5 point favorites. The moneyline for that game is probably around -800. You’d have to bet $800 to win $100.

A spread bet gives you the chance to pick the Chiefs at -110 odds at a chance of winning more money if they win by at least 14.

How to Read Moneyline Bets and Odds

The moneyline is one of the most popular betting strategies. It’s also one of the easiest to learn. Worrying about point spreads or other complicated betting concepts is no longer necessary. You just need to pick the winner, and you’re good to go. The only thing that matters is if you see the team you bet on win or lose.

However, because these kinds of bets are so simple and easy to understand, they usually come with lower odds than other betting types. This is because you need to risk more money to win a given amount. Let’s take a look at an example.

Suppose you want to bet on the New York Yankees in a game against the Boston Red Sox. The moneyline odds work something like this:

Yankees -130

Red Sox +110

The first number on the sportsbook is always the implied probability of winning the game for the team listed first, and the second number is a high likelihood of winning for the team listed second. In this case, the Yankees are favored to win (indicated by the minus sign), and the Red Sox are the underdog (indicated by the plus sign).

The negative number indicates how much you must risk on the Yankees ($130) to win $100. However, if you’re going to take on the underdogs, you only need to place a bet amount of $100 for a payout of $110.

How to Read Over/Under Odds

Over/under betting is a type of bet where a sports bettor attempts to predict whether the total number of points scored in a game will be over or under a specific number listed by a sportsbook.

Let’s say the total is set at 45.5 points for an NFL game. If you bet the over, you are predicting that the final score will be a combined 46 points or higher by both teams. If you bet the under, you are betting that the final score will be 45 points or lower.

How to Read the Lines for Different Types of Sports

NFL Betting Lines

The NFL is the most popular sport in betting circles around the United States. Football has two common types of betting lines: the point spread and the moneyline. The point spread is used to even out the playing field between two unevenly matched teams. Let’s say the Cleveland Browns are playing the Buffalo Bills.

Suppose the Bills are a much better team than the Browns. This means they are most likely to win. The point spread is used to level the playing field, it might be something like this:

  • Browns +8.5
  • Bills -8.5

This means if the Bills win by 9 points or more your bet wins. You will lose your bet if the Bills lose or if they only win by 8 points or less. Sometimes you will see a point spread that falls on a whole number such as 7.

If the Bills were -7 point favorites and they won by 7, that’s called a push and you would get your money back. They would have to win by 8 or more for you to get your payout.

Totals are another common NFL bet type. You might see the over/under on the Bills-Browns game to be 52. If you take the under, you are expecting both teams to combine for 51 points or less. So if the score ended up being 24-20 and you picked the under, you would win because it was eight points lower than the total line.

We talked a little bit about how to read moneyline odds above. These odds are also available in NFL games. You might see the Chiefs at -225 vs the Texans. A $225 bet would win you $100. If the odds are -300 and you wanted to win $100, $300 is how much you’d need to bet.

NBA Betting Lines

The NBA is also an extremely popular sport to bet on. If you are looking at getting into NBA betting it’s important you know how to read the odds correctly and what the American odds indicate. Let’s say the Golden State Warriors are playing the Cleveland Cavaliers. The Warriors are favored to win by 7.5 points.

Similar to our NFL examples above, it means that the Warriors need to win by more than 8 points for you to earn from your bet. You will lose your bet if the Warriors lose or if they only win by 7 points or less.

The moneyline works the same way as it does in football. So the odds would look something like this:

Warriors -350

Cavaliers +290

This means that if you decided to bet on the Warriors to win straight up, you need to bet $350 for a payout of $100. On the flip side, if you bet on the Cavaliers, you must bet $100 to win $290. Another example might be you see the Detroit Pistons at +200 odds to win vs the Lakers. Betting $100 on the Pistons will win you $200.

MLB Betting Lines

Major League Baseball is growing in the betting market and you will see MLB betting lines work similarly to the NFL. The numbers are obviously much smaller for spreads or totals. In baseball, the spread is called the run line. The run line for all baseball games is always -1.5 and +1.5.

This leads many people to bet moneylines in baseball. On top of this, it is more common to see an underdog win a game in baseball than in football. They have a better shot of winning than in other sports.

Baseball includes totals as well. The over/under might be something like 11.5. You are looking at how many runs both teams score combined. If a game ends 7-6, it hit the over.

Are the Lines the Same at All Sportsbooks?

No, the lines at different sportsbooks will vary slightly as they might use a different technique to calculate sports odds. Sports odds are most commonly set after bookmakers compare the power ratings of each team to come up with a rough estimate of what the line should be.

Then, they set negative or positive odds based on their analysis of the game and public betting activity. As you start understanding betting, you’ll see how some sportsbooks might have slightly different odds compared to others.

So, Why Do Sports Betting Lines Move?

Typically, sports betting lines/odds are displayed the day before the game to allow bettors ample time to research the teams and make informed decisions. But they sometimes change before the game. Odds are displayed several days in advance for NFL and college football games.

Bettors can see the odds change throughout the week for football so maybe the Bills were a -150 to win on Thursday, but by Sunday morning they were a -160. What you would need to bet to win $100 went up.

Now, sports betting lines move for two main reasons:

Public betting action

A line will move based on how the public is betting. If the Bills are favored at -220 vs the Browns and a large number of bettors keep placing wagers on the Bills, you will see the line change to -230 or -240. The same concept would apply to a spread bet. You would see the line shift based on what side is more heavily bet on to balance it out.

New information

A sportsbook might change a line after there is information that might impact the game. A common example would be an NFL spread changing because an injury was announced during the week. You could see a line change significantly if a starting quarterback is out with an injury.

Why Should You Shop Sports Betting Lines?

Understanding how to read odds is a crucial skill, but line shopping is vital if you want the best value for your buck. Let’s consider this example:

An NFL bet on PointsBet lists the New England Patriots as 7-point favorites against the New York Giants. FanDuel puts the Giants as 7.5-point favorites in the game. It doesn’t seem like much, but if you wagered on PointsBet and the Patriots lose 21-14, a +7 bet won’t pay. But all bettors with a FanDuel ticket will be smiling due to the half-point difference.

Ready to Start Betting?

Now that you know how to read betting lines, you’re ready to join a sportsbook. Remember to shop for the best lines, research your picks, and calculate how much you stand to win if you bet a certain amount.

Check out a sports betting site and online sportsbooks to familiarize yourself with common odds even before you start betting. There’s a lot to learn for anyone who is new to sports betting so a good place to start is to learn how to read odds.

Betting Odds FAQ

What is a betting line?

A betting line is a number set by oddsmakers to represent the expected outcome of a particular event. The line is used as a reference point for people placing bets on the event and can be used to calculate the potential payout for a given bet based on the odds and the amount of money wagered.

For example, if a football game has a betting line of +7, it means that the team considered to be the underdog is expected to lose by seven points. If you bet on that team and they win or lose by fewer than seven points, you would win your bet. This is why it’s important to know how to read a betting line.

When are sports betting lines released?

It varies among sports. Basketball and hockey, for example, have multiple games played each week. Due to this, the final odds are often posted by sportsbooks the morning before the game.

Sports like football usually have one game per week. Once the two contending teams finish this week’s game, it’s common to see the odds for the next game.

What is the hardest sport to bet on?

You might find different opinions but some people will say baseball due to its high unpredictability and a large number of games per week. Many new bettors will look to the NFL or NBA when getting started.

Ultimately, it’s put to you and how much you understand the odds. If you know what you are doing and like the odds better, you can bet on the sport you are most comfortable with.

WRITTEN BY

Sam Russell

Sam hails from Grandville, Michigan, and was Betsperts' first employee back in January 2019. He has a rich sports background, including playing baseball at Central Michigan before covering high school sports and working with the Orlando Magic. He earned his degree from Central Michigan University and was a member of the 2010 MAC Championship baseball team.

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