Odds News: The Basics About Major League Baseball Odds
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In 2018, the Supreme Court struck down the federal ban on sports betting. Since then, legal sports gambling has exploded in the United States. Currently, wagering on Major League Baseball (MLB) is legal in more than two dozen states. This has brought baseball betting to the mainstream, and fans can now place bets in person and online where applicable. In short, betting on baseball is becoming more and more popular.

The Best Way to Bet on Baseball

There is no best way to bet on baseball, but understanding how to read the odds is a critical first step for anyone serious about placing a bet. MLB lines can be tricky to understand. By learning how oddsmakers calculate the odds, you can place smarter bets and give yourself a better chance to win.

Generally speaking, bookmakers begin by looking at each team’s performance. They then consider factors like weather, injuries, home-field advantage, trends, and even intangibles to determine a number that represents each team’s chance of winning. They then look at what other bookmakers are doing and adjust their numbers accordingly.

Understanding the Numbers

The first step is to understand what the numbers mean. When you see a baseball betting line, you will generally see numbers next to each team.


The first number is usually the “moneyline.”

The moneyline is represented by either a positive or negative integer, representing how much money needs to be wagered to win $100. A positive number represents a bet, and a negative number represents a lay bet.

For example, in a game between the Los Angeles Dodgers (-250) and the San Diego Padres (+195). The Dodgers are the -250 favorites, meaning you will need to lay $250 to win $100, while you can bet $100 to win $195 by backing the underdog Padres.

In another example, the Philadelphia Phillies (+150) are playing the Houston Astros (-190). Your $100 bet on the Phillies would pay you $150 if they win the game, while you would need to lay $190 on the Astros to win $100.

It’s important to note that you don’t have to bet dollar amounts to match the odds exactly. Sportsbooks fractionalize moneyline bets meaning if you only bet $50 on the Phillies in the above example, your payout would be $75.

Run Line or Run Spread

You’ll usually see the second number, the run-line (also called the run-spread). The standard run-line spread is always 1.5 runs. The favorite will always be +1.5 runs and will need to win by two or more to be graded as a successful bet, and the underdog is always +1.5 and will have to win the game or lose by just a single run.

As with the money line, the run-line payouts are relative to the number 100, with the favorite run-line side being a negative integer and the underdog being positive.

Over Under Betting

The over/under refers to the number of runs two teams will combine to score in a game. This bet option allows you to bet on the total runs scored to be either over or under the number set by the oddsmakers. The over/under number in baseball is always represented by half a run to prevent ties.

Bets on the over/under are also relative to the number 100 and usually open at -110 aside.

Understanding Oddsmakers

The final step is understanding how these numbers are all calculated. To do this, we need to look at probability and public perception. Probability is a big part of oddsmaking. Oddsmakers want to ensure that for every dollar wagered on one team, they make a profit no matter which team wins.

In other words, they want equal action on both sides.

To do this, they use the “book percentage.”

The book percentage tells them what percentage of bets they need on each team to make a profit, regardless of which team wins. For example, let’s say that 55% of people are betting on Team A, and 45% are betting on Team B. For the bookmaker to make a profit, they would need Team A to lose more than 45% of the time and Team B to lose more than 55% of the time.

The last step is understanding public perception. The public tends to overvalue favorites and undervalue underdogs. This means that oddsmakers will frequently set lines to encourage more betting action on underdogs than favorites, even though favorites may be more likely to win. By understanding how oddsmakers set lines, you can identify value bets where you are more likely to win than the odds suggest.

To calculate MLB odds, you need to know the probability of each event. Once you have the probabilities, you can use a simple formula to calculate the odds. By understanding how MLB odds are calculated, you can place smarter bets and give yourself a better chance at winning.