What Is the 10 and 15-Run Rule in Baseball?

Unlike most other games, baseball and softball are sports where the game doesn’t have a designated time limit. It’s structured to have three outs per inning before the team playing defense (whether this is the home team or the visiting team) steps up to the plate.

Because of this, specific run rules need to be put in place for the game to not carry on for too long. This is especially so in Little League softball and baseball when they need to play less innings.

A shorter game can end after three innings or two and one-half innings.

Another way that the game is sped up is that a pitcher is given warm-up pitches between innings. 

The 10-run rule, also called the mercy rule, has been in place for a long time in the regular season of play. The 15-run rule was officially written in the Little League rule books in 2018.


What Is the 10-Run Rule?

The 10-run rule, also called the mercy rule, the knockout rule, and the slaughter rule is one where a game in a regular league season is put to an end when one team (home team or visiting team) has a lead of ten runs or more after a certain number of innings. 

This is applied when the conventional means of recording outs proves a challenge to the two teams.

It’s commonly referred to as the mercy rule as you can interpret it as an act of mercy to the team with the least runs, saving the team from embarrassment by the opponent with the lead.

The rule is not mandatory for Little League games, but it’s recommended since a failure to implement it can lead to a massively inflated final score when the game is completed, especially for the team with the victory. Though the 10-run rule varies in how different local leagues choose to implement it, the most common implementation of it is when there are two innings left before the end of a regulation game.

In a high school baseball league, the game ends immediately after five innings of play when one team already has a lead of 10 runs or more. This is because high school games are usually set to have seven innings.

Most Little League games are set to have six innings, meaning the rule will take effect after four innings. You will almost always see the implementation of the rule in Little League baseball as children don’t have the capacity to play the same amount of innings or until games end. 

They can also concede early to the opponent due to being easily discouraged by a huge score if they’re on the opposing team.

One thing to keep in mind about the rule is that no matter how far ahead one team is, the rule doesn’t take place until after the specified inning of play. In the case of Little League baseball, if one team has a lead of ten runs after three innings, the rule still won’t take effect until four innings are completed.

In the case of a high school baseball league, if the home team is ahead by ten runs or more after the top half of the fifth inning, the game is over. In high school softball in America, the mercy rule of 10 runs in five innings is used. 

The home team also has an advantage as it’s allowed one more turn at bat in case it’s behind in a Little League game. 

On the other hand, if the home team is ahead by ten runs or more after three and one-half innings in the case of lower leagues, or four and one-half innings in the case of a high school league, they will not play any more innings. The official will end the game early and the opponent will have to concede.

If the home team has a lead of ten runs, the game will end directly after the tenth run is scored in an inning. It doesn’t matter if other runs have been scored on that particular inning. 

Also, in the bottom half of an inning, when a home team reaches the set number of runs at bat, and the qualifying run is scored, the umpire calls the game, and no more innings are played.

What Is the 15-Run Rule?

In 2018, the 15-run rule was officially written in the Little League rule book. Similar to the above 10-run rule, teams can now choose to set their mercy rule at 15 runs or more instead of 10 runs or more.

But while the 10-run rule takes effect if one team is ahead after the fourth inning, the 15-run rule takes effect if the winning team is in front after the third inning (or two and one half innings if the home team is ahead) in the Little League. 

This means the coaches of the teams in the league with the least runs will concede victory early. If the visiting team has a 10-or 15-run lead, the home team is required to bat in its half of the inning. 

It’s important for parents to understand these rules for them to be in line with the pace of play in their local league.

A league can choose to implement either the 10-run rule or the 15-run rule. But even if a league chooses to not implement the rules during the regular season, the rule book states that it’s mandatory during International Tour league games.

What Are the Advantages of Either Run Rules?

1. There’s No Dragging of Games

Because of the nature of baseball and the fact that it doesn’t have a specified game time, a game could go on for a long time before determining the winner. The run rules eliminate the wait while still providing an effective and accepted way for teams to decide when to end games or when a baseball game is too far gone.

2. The Rule Saves the Losing Team From Embarrassment

Speaking of games that are too far gone, a failure to implement either run rule in a local league can lead to lopsided scores that are unrealistic. 

And if one team keeps on running up the scoreline, the team with the least runs, whether this is the home team or the visiting team, is sure to feel embarrassed and even discouraged from continuing with the game.

Not only that, but a lopsided game is not fun. It’s especially so if you’re on the team that’s not in the lead. 

You can also get a bit bored with the game and the score, even if you’re already on the path to victory.

3. The Rule Saves Both Teams From Unnecessary Fatigue Levels

Whether you’re on the home team or the visiting team, if either run rule is not implemented during a local league game, you’re sure to get tired after spending such a long time playing baseball. 

This is especially so if you’re a batter or a pitcher playing defense as all that swinging is sure to make your arms sore afterward.

Is There a Run Rule in Major Leagues?

There is no run rule in MLB for the simple reason that the players are professionals with a lot of training and experience in the game. As a result, they can’t rely on any kind of mercy during the game and can handle more innings.

This is also because the players in the MLB league have the talent to turn the game at any point. You will, however, come across games in the minor league that have an implemented mercy rule.


The 10-run rule and the 15-run rule have their place in a regular season of modern baseball and softball leagues. 

They’re especially advantageous in leagues played by children as they are likely to not get discouraged by the game if they’re playing three and one-half innings or half a usual game length. Otherwise, it can lead to them losing interest in the sport altogether.

For the parents out there, make sure to take the time to understand the rules. Otherwise, you’ll be surprised when you see a local league match end way earlier than the games you see on TV.