When the Supreme Court of the United States (SCOTUS) struck down the federal ban on sports betting in 2018, legal sports gambling grew by leaps and bounds. Wagering on Major League Baseball (MLB) is now legal in more than two dozen states. With baseball betting going mainstream, fans can now place bets in person and online on their favorite teams all year round.
There are many ways to bet on the game, and understanding the odds is a critical first step for anyone placing a bet. Some baseball lines and prices can be tricky to understand, but knowing how bookmakers calculate their numbers gives you 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 Bet Types
There are several ways to bet on baseball games, including the moneyline bet, the run-line bet, and over/under wagering.
Moneyline Bets
The moneyline is represented by either a positive or negative integer. This number corresponds with how much money needs to be bet to win $100. A positive number represents a bet on the underdog, and a negative number represents a lay bet on the favorite.
For example, at the sportsbook at BetMGM Ohio, there is a game on the board between the Los Angeles Angels (-250) and the San Francisco Giants (+195). The Angels 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 Giants (the underdog).
The second example is in reverse order. The New York Mets (+150) are playing the Toronto Blue Jays (-190). Your $100 bet on the Mets will pay you $150 if they win the game, while you need to lay $190 on the Blue Jays to win $100. Here the Mets are the underdog and the Blue Jays the favorite.
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, and 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 percentage book 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.