MLB Betting Rules at MA Sportsbooks

Now that Massachusetts allows regulated online sports betting, Boston Red Sox fans can legally bet on their favorite team (and much more).

Here’s a quick walkthrough of all the basic sportsbook rules for betting on MLB games at online sportsbooks.

When does an MLB bet “have action?”

The result must be official for the bet to have action for MLB games. Any game that has an official outcome should stand unless the sportsbook states otherwise for any reason.

Bets on parts of the game, such as the first five innings, must have the inning or innings officially completed. Sportsbooks can also turn down a bet or payout for many reasons, including errors on their part.

Basic MLB betting rules in Massachusetts

The following MLB sportsbook rules apply for baseball games that are impacted by unexpected circumstances during the season, such as changes of venue, postponements, and suspensions.

Rules for date or venue changes

Most prominent sportsbooks, such as the MGM sportsbook, require that regular-season games take place on the scheduled date and at the planned venue for the bet to stand. Otherwise, they typically offer refunds.

Some places, like DraftKings, rely on the home team designation rather than the venue, so any bets could stand if the ballpark changes, provided the home team is still the home team.

Rules for shortened or canceled MLB games

Baseball teams experience shortened and suspended games every season due to inclement weather. MLB rules designate an “official game” after 5.0 innings or 4.5 innings if the home team is winning. Most moneyline bets have action if the game lasts at least this long. So, for instance, correctly betting on the winner of a game that ends due to rain after seven complete innings will probably pay.

Run totals and run lines pay at the discretion of the sportsbook, as they may require all nine innings or 8.5 if the home team is ahead. Suspended games usually stand if it resumes within a specific time frame. If not, a sportsbook may void and refund bets, depending on its own particular baseball betting rules.

All bets receive a refund for a canceled or postponed game. If a game begins but never resumes or ends after a break in play, the sportsbook may void and refund bets at its discretion.

Rules for shortened seasons

In the event of a shortened regular season, futures bets on a team’s win total are subject to the sportsbook’s required number of games played for the bet to stand. It is usually a percentage of the season. For example, at DraftKings it is 98% of a team’s scheduled games.

A shortened season will not invalidate most futures bets, so long as the season finishes and advances to the playoffs. Bets on division winners, league winners, and the World Series champion will typically remain valid even in a shortened season.

MLB betting rules by wager type

There are a number of different ways to bet on baseball games, each with its own specific set of betting rules. Here are the main MLB betting rules and regulations you should know before placing your bets at the sportsbook:

Point spread

MLB spread bets are also known as “run line” bets. The standard MLB run line is 1.5.

If the Red Sox are -1.5 favorites against the Baltimore Orioles, they must win by two runs to cover. If they’re +1.5, they cover if they lose by one run or win the game. Should a game see extra innings, the bet uses the final score.


A moneyline bet is a pick of a team to win regardless of score differential. Results from extra innings count unless the bet was only for the first nine innings.


These bets, also known as totals, are wagers on the number of combined runs in a game. You bet whether the total runs will go under or over a line that the sportsbook sets. All runs scored in extra innings count toward the game’s run total. You can also bet the over/under on a season’s win total.

Live betting

Odds shift during a game, and live in game betting allows players to bet on them. Live bets generally are subject to the same rules as betting before the game. The game must be official for the bet to count, and extra-inning outcomes count toward the results.

Extra inning betting

Extra innings count for any bets on a game unless the sportsbook states otherwise. A shortened or suspended game while in extra innings follows the same MLB house rules as any other game.

Parlays & same-game parlays

Every leg of a parlay (or same game parlays) must win for the bet to pay unless the sportsbook rules state otherwise. If the sportsbook voids one leg of the parlay, the entire parlay may cancel. Or the sportsbook may just remove that particular portion of the parlay and adjust the overall odds for the rest.

Game and player prop rules

Game prop bets usually require a game to be official or reach a designated point unless the bet is independent of a game’s length. If the game doesn’t reach the required number of innings, the bet would have no action and likely result in a refund.

For MLB player props, bets become official if the particular player meets the appearance requirement of the sportsbook, typically one pitch thrown for pitchers and one plate appearance for position players. These bets generally are subject to the official game rules unless the game length doesn’t impact the bet.

Grading bets, procedures for returned/pushed bets

A graded bet is a wager that a sportsbook has marked as a win, loss or push. Payouts don’t happen until after the sportsbook grades a bet. For games, that means until after the final out. For futures, such as division winners, it usually will take until the season ends, even if the result looks inevitable.

Some prop bets can be open to multiple interpretations, making them more difficult to grade. Legal MA sportsbooks are safer options here because they’re legally bound to fairness and transparency standards. For them, a refund is better than legal action. Likewise, paying out a disputed bet can result in good publicity.

One example came in February of 2022, when a stat correction resulted in Nikola Jokic of the Denver Nuggets getting a triple-double two days after the game happened. FanDuel Sportsbook subsequently received praise for changing affected bets to wins, while some competitors didn’t.

What happens when sportsbooks make mistakes?

Sportsbooks sometimes make mistakes and accidentally post incorrect sports lines and odds. They’ll fix the error and offer a refund if this happens. An error that goes unnoticed until after the game will likely not see a payout.

Sportsbooks have specific policies to protect themselves from these mistakes. So, if you see the Red Sox as 15-run underdogs, don’t expect to benefit unless the sportsbook feels generous.

However, there are cases of sportsbooks honoring mistaken odds. An instance of this occurred in 2018 when a glitch allowed someone to bet on the Denver Broncos to win at 750-1. FanDuel could’ve legally voided the bet but instead paid the winnings.

What happens when stats change after the game?

When stats change retroactively, the bets do, too. A player might reach first base on an error during a Red Sox game. After the game, the official scorer may change that error to a hit. When these stat changes occur, the sportsbooks may change the bet grade to a win. Offering refunds or upholding the initial outcome is also possible.

What are correlated plays, and why can’t you make them?

Correlated plays are paired bets where the outcome of one is highly influential on the outcome of the other.

For example, if the Red Sox betting odds had them as underdogs, you couldn’t take them on the moneyline and the run line. Any underdog that wins on the moneyline would also have covered the run line in every circumstance. Sportsbooks eliminate correlated options to reduce their risk in offering bets.

What are the rules for minimum and maximum MLB bets?

The minimum and maximum bet you can place will depend on the sportsbook and the type of bet. At BetMGM, the betting starts as low as $0.50. At FanDuel, there is a $5 minimum to bet. Some sportsbooks don’t limit bet amounts, but they can refuse a bet at their discretion.

Rules for bonus bets and other bonuses

Sportsbooks give players special offers such as site credit and bonus bets to win new customers. Once you sign up, you usually won’t be able to withdraw your winnings immediately. Sportsbooks have playthrough requirements before customers can withdraw, and it varies by book:

  • BetMGM MA Sportsbook bonus: Refundable first bet up to $1,000; 1x playthrough requirement on any refund you receive.
  • DraftKings MA bonus: First deposit match up to $1,000; 25x playthrough requirement on bonus funds.
  • BetRivers MA Sportsbook bonus: First deposit match up to $500; 1x playthrough requirement on bonus funds.

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