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What is “SU” in Baseball? A Quick Guide

Each sport tends to have its own set of acronyms and it takes some time to learn what those acronyms mean. Baseball is no different. In baseball, one of the acronyms that have been showing up more often is “SU” when referring to a player. What does “SU” mean in baseball?

In baseball, “SU” means “Set Up Pitcher” or “Set Up Man”. A Set Up Pitcher is a relief pitcher who pitches before the Closer, usually in the eighth inning. Set Up Pitchers normally pitch one inning and are considered the second-best relief pitcher on the team.

Youth pitcher in a blue and black uniform taking signs from his catcher

In the early days of baseball, Set Up Pitchers were not really a type of relief pitcher because there was no concept of a Closing Pitcher. Set Up Pitchers became more prominent when Closing Pitchers became more prominent. As the role of a Set Up Pitcher progressed, baseball came up with a new statistic to measure the effectiveness of a Set Up Pitcher – the Hold (HLD).

What is the “SU” Position in Baseball?

Blank baseball lineup on a small paper napkin that uses peanuts to show the defensive position of players

When you look at a baseball roster you will see a lot of different acronyms for defensive players. For example, 2B stands for second base and CF stands for center field. One acronym you won’t see on a roster is “SU”, but sometimes this acronym will show up next to a players’ name.

Seeing “SU” next to a player’s name is also very common in video games like MLB The Show and Out of the Park Baseball. Because of these video games, the acronym “SU” has gained some popularity. But what is the SU position in baseball?

In baseball, the SU position is an acronym for describing a specific type of relief pitcher. “SU” stands for “Set Up Pitcher” or “Set Up Man”. A relief pitcher who is a Set Up Pitcher typically enters the game in the eighth inning and will pitch for one inning before getting replaced by the Closer.

For a pitcher, SU means they are the Set Up Pitcher and they can expect pitch later in the game. Being an SU pitcher also means they can expect to pitch for roughly one inning before the closer comes in to finish the game.

After understanding what a Set Up Pitcher is in baseball, the next thing people wonder about is what the roles and responsibilities are of a Set Up Pitcher.

The Purpose of an “SU” Pitcher

As a general rule, Set Up Pitchers are thought to be the second-best relief pitcher on the team, behind the Closer. As the second-best relief pitcher on the team, there are a handful of responsibilities assigned to Set Up Pitchers.

Set Up Pitchers Are Expected to Pitch for One Inning

One of the distinguishing factors that separates a Set Up pitcher from any other type of relief pitcher is that a Set Up Pitcher will typically throw for one inning and that one inning will come just before the closing pitcher comes into the game.

Sometimes Set Up Pitchers will pitch for more than one inning, but it’s far more common that a Set Up Pitcher pitches just one inning.

Set Up Pitchers can be thought of as a Closer that pitches before the actual Closer. This makes sense because it’s also common for Closers to have started their careers as a Set Up Pitcher.

Set Up Pitchers Maintain the Lead for the Closer

Set Up Pitchers don’t get as much of the glory as Closing Pitchers because the role of the Set Up Pitcher is to maintain the score and then turn over the rest of the game to the closing pitcher.

Set Up Pitchers typically come into the game during a Save Opportunity, but they end up being removed from the game before completing the game and getting credit for a Save.

Relief pitchers used to be judged by how many Saves they would acquire, but because of how a Set Up Pitcher was being utilized, baseball came up with a Hold (HLD) statistic to track how well these Set Up Pitchers were performing.

The Best Set Up Pitchers Become Closers

A lot of pitchers who are Closers started off as being a Set Up Pitcher.

A Set Up Pitcher and a Closer have a lot of characteristics in common – both roles specialize in pitching for a short amount of time (usually one inning) and both are considered to be great relief pitchers.

Because of how much the roles of a Set Up Pitcher and a Closer overlap, it’s common for a Set Up Pitcher to transition to a Closer.

In fact, Mariano Rivera was a Set Up Pitcher during his second MLB season in 1996. Then in 1997, he became the Closer for the New York Yankees.

Set Up Pitchers Are Measured by the Hold (HLD) Statistic

Set Up Pitchers and Closing Pitchers were not too common in the early days of baseball, but as the value of a Closing Pitcher increased, so did the value of a Set Up Pitcher.

Eventually, people wanted a way to track how well a Set Up Pitcher was performing. In the 1980’s, the Hold (HLD) statistic was invented to help people understand how well non-closers were performing.

To earn a Hold, a pitcher must enter the game during a Save Opportunity and keep the lead. This is the exact scenario where a Set Up Pitcher enters the game and has become one of the ways to measure the success of a Set Up Pitcher.

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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.