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Baseball’s LRP and MRP And When to Use Each

Whether it’s discussing a position player, a batter, or a statistic, the sport of baseball is full of acronyms. There are some acronyms that are fairly common, like DH, 1B, or AB, but there are also some acronyms that aren’t as common. Two baseball acronyms that are not discussed regularly are LRP and MRP. What do LRP and MRP mean in baseball?

In baseball, LRP and MRP are acronyms for Long Relief Pitcher (LRP) and Middle Relief Pitcher (MRP). LRP’s are used when there are a lot of innings left in a game while MRP’s are used in the sixth and seventh innings of a game.

Silhouette of a pitcher in the windup at dusk

Long relief pitchers and middle relief pitchers are used in specific scenarios during a game and they are important roles towards helping a team win. The acronyms of LRP and MRP have also gained some popularity in baseball thanks to video games like MLB The Show.

LRP and MRP in Baseball

Long relief pitchers and middle relief pitchers sound like they may have overlapping roles, but there are some differences between the two types of relief pitchers. What’s the difference between LRP and MRP in baseball?

Long Relief Pitchers (LRP) relieve a Starting Pitcher before the 5th inning of a game while Middle Relief Pitchers (MRP) relieve any pitcher in the 6th or 7th inning. Long Relief Pitchers tend to be former starting pitchers and are able to throw more innings than a traditional relief pitcher.

While it’s possible for both a long relief pitcher and a middle relief pitcher to pitch in the same game, it’s not always needed if a long relief pitcher is able to continue throwing until the team is ready for a Set Up Pitcher (SU) or a Closer (CL).

Teams Use a Long Relief Pitcher (LRP) Before the 5th Inning

There is not a set rule in baseball for when a manager or a coach has to use a specific type of relief pitcher, but there are some generalities that we can use to classify a pitcher as LRP. What Does LRP Stand for in baseball and when should you use an LRP?

In baseball, LRP stands for Long Relief Pitcher. Long Relief Pitchers are used before the 5th inning of a game and are expected to throw several innings. Oftentimes, Long Relief Pitchers are used in the first three innings of a game to relieve a struggling starting pitcher.

Long Relief Pitchers are expected to throw multiple innings so a lot of Long Relief Pitchers are former Starting Pitchers. One of the benefits of this relief pitcher being able to throw multiple innings is that Long Relief Pitchers allow a team to rest the remainder of their bullpen while still giving their team a chance to win the game.

Not all pitchers have great days on the mound so Long Relief Pitchers are the most beneficial when replacing a struggling Starting Pitcher. Because a lot of Long Relief Pitchers used to be starting pitchers, they are used to pitching for multiple innings.

Teams Use a Middle Relief Pitcher (MRP) in the 6th and 7th Innings

Managers are able to use any type of relief pitcher in any scenario they see fit, but there are some generalities associated with being an MRP in baseball. What does MRP stand for in baseball and when should you use an MRP?

In baseball, MRP stands for Middle Relief Pitcher. Middle Relief Pitchers are used in the 6th and 7th innings of a game as a way to bridge the gap between the Starting Pitcher and a Set Up Pitcher or Closing Pitcher.

Middle Relief Pitchers typically throw for no more than 2 innings and they are replaced by either a Set Up Pitcher or a Closing Pitcher later in the game. When they get replaced depends on how well they are performing and where the opposing team is at in their batting order.

Sometimes Middle Relief Pitchers come in as early as the 5th inning, but it is more common they enter the game at some point in the 6th or 7th inning.

Additional Acronyms for Long Relief Pitcher and Middle Relief Pitchers

Believe it or not, there are actually some other acronyms used in baseball to signal whether a pitcher is a long relief pitcher or a middle relief pitcher. Some of these acronyms are also used in video games like Out of The Park Baseball (OOTP) and MLB Tap Sports Baseball.

What is MiR and MR in Baseball?

In baseball, MiR and MR stand for Middle Relief Pitcher. A Middle Relief Pitcher typically enters the game in the 6th or 7th inning as a way to bridge the gap between the previous pitcher and a late-inning pitcher, which is usually a Set Up Pitcher or a Closer.

What is LoR and LR in Baseball?

In baseball, LoR and LR stand for Long Relief Pitcher. A Long Relief Pitcher will enter the game for the Starting Pitcher before the 5th inning, but typically will enter the game within the first 3 innings of a game.

MR vs SR in Baseball

A common question that comes up is, what does MR and SR mean in baseball?

In baseball, MR stands for Middle Relief Pitcher while SR stands for Short Reliever.

Both Middle Relief Pitchers and Short Relief Pitchers are expected to throw for 1-2 innings, but Middle Relief Pitchers generally enter the game in the 6th or 7th inning while a Short Relief Pitcher does not have a typical time they enter the game.

LRP vs MRP vs SU

Once you start diving into the different types of relief pitchers, you may come across some different acronyms that describe these different relief pitchers. What do LRP, MRP, and SU stand for in baseball?

In baseball, LRP stands for Long Relief Pitcher, MRP stands for Middle Relief Pitcher, and SU stands for Set Up Pitcher. LRP enters the game before the 5th inning, MRP enters the game in the 6th or 7th inning, while SU enters the game in the 8th inning.

Managers can use their relief pitchers whenever they would like, but those are the innings in which each type of relief pitcher typically enters a game.

Learn more about an SU pitcher in baseball.

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Steve Nelson

I'm the owner of Baseball Training World. I live in Denver, Colorado and I enjoy playing baseball in an adult baseball team in the surrounding area. Read more about Steve Nelson.

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  1. Pingback: Types of Pitchers in Baseball: SP, RP, and CP Explained – Baseball Training World

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