What Does SU Mean in Baseball? [Decoding Baseball Jargon]

John Means

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What Does SU Mean in Baseball

Baseball, often called America’s pastime, is a sport known for its rich history, traditions, and unique jargon. From home runs to strikeouts, baseball has its own language that can sometimes confuse newcomers and casual fans. One term that often raises questions is “SU.” So, what does “SU” mean in baseball?

In baseball, “SU” is an abbreviation used to refer to a relief pitcher’s role called the “setup” pitcher. The setup pitcher, also known as the setup man or setup reliever, is a crucial component of a team’s bullpen. 

Let’s dive in and find out all about setup pitchers.

What Does SU Mean in Baseball?

In the context of baseball, “SU” is an abbreviation that typically stands for “Set-Up.” It refers to a relief pitcher who is used in a game to bridge the gap between the starting pitcher and the closer. 

The SU pitcher is typically brought into the game in the late innings, often in the 7th or 8th inning, with the purpose of maintaining or extending the team’s lead.

The role of the SU pitcher is crucial in a team’s bullpen strategy. They are responsible for preserving the lead and handing the game over to the closer, who is considered the team’s best reliever and is tasked with securing the victory in the final inning(s).

SU pitchers are often known for their ability to throw hard, induce strikeouts, and handle high-pressure situations. They need to be effective in getting opposing batters out quickly to limit the chances of the opposing team staging a comeback.

The SU role has become more prominent in recent years as teams have recognized the importance of a strong bullpen. By effectively managing the late innings with a reliable SU pitcher, teams can increase their chances of winning games, especially in close contests.

How Is the SU Position In Baseball?

The set-up (SU) position in baseball refers to the role of a relief pitcher who is typically deployed in the late innings of a game to bridge the gap between the starting pitcher and the closer. Here are some key aspects of the SU position:


The SU pitcher is usually brought into the game in the 7th or 8th inning, depending on the situation. Their primary objective is to preserve a lead or keep the game tied until the closer can be brought in to finish the game in the 9th inning.

Skill Set

SU pitchers are often known for their ability to throw hard and generate strikeouts. They are expected to have good command of their pitches and the ability to handle high-pressure situations. 

Many SU pitchers have a repertoire of pitches that includes a mix of fastballs, breaking balls, and off-speed pitches to keep hitters off balance.


The SU position has gained increasing importance in recent years as teams have recognized the value of a strong bullpen. By having a reliable SU pitcher, teams can effectively shorten the game, making it more manageable for the closer to seal the victory.

Matchup-Based Usage

Managers often utilize SU pitchers strategically based on matchups against specific batters. For example, if there are several left-handed hitters due up in the upcoming innings, a left-handed SU pitcher may be called upon to exploit their weaknesses.


SU pitchers’ effectiveness is evaluated based on various statistical metrics. Some common statistics used to assess their performance include earned run average (ERA), strikeouts per nine innings (K/9), walks plus hits per inning pitched (WHIP), and inherited runners stranded percentage (IRS%).

Evolving role

The role of the SU pitcher continues to evolve in modern baseball. Some teams have experimented with using their best relief pitcher, regardless of the inning, in high-leverage situations earlier in the game. This approach, known as “bullpenning” or “openers,” challenges the traditional roles of starters, set-up pitchers, and closers.

Why Does the SU Pitcher Do In Baseball?

the SU Pitcher Do In Baseball

Source: wezen-ball.com

The primary role of the SU (Set-Up) pitcher in baseball is to bridge the gap between the starting pitcher and the closer, ensuring a smooth transition from the middle to the late innings of the game. Here’s what the SU pitcher typically does:

Maintain the Lead

When the starting pitcher exits the game, the SU pitcher is responsible for preserving any lead that the team has built. Their goal is to keep the opposing team from scoring runs and potentially erasing the lead.

Hold the Game

If the game is tied when the SU pitcher enters, their objective is to keep the score level and give their team an opportunity to regain the lead later in the game. Their performance can significantly impact the momentum and outcome of the contest.

High-Pressure Situations

SU pitchers often find themselves in high-pressure situations, such as inheriting baserunners or facing the heart of the opposing team’s lineup. They must be able to handle these pressure-filled moments and get crucial outs to keep the game under control.

Set Up the Closer

The SU pitcher’s ultimate objective is to hand the game over to the closer, who is typically the team’s best relief pitcher. By maintaining the lead or keeping the game tied, the SU pitcher paves the way for the closer to enter the game in the final inning(s) and secure the victory.

Get Key Outs

SU pitchers are expected to retire important batters, especially those who pose a significant threat to their team’s success. They often face the opposing team’s best hitters and must use their pitching repertoire and strategies to induce outs efficiently.

Matchup-Based Usage

Managers may deploy SU pitchers strategically based on matchups. For example, if there are particular batters in the opposing lineup who struggle against a specific type of pitching (e.g., left-handed batters against left-handed pitchers), the manager may bring in a suitable SU pitcher to exploit that weakness.

Overall, the SU pitcher’s role is critical in maintaining leads, holding the game in check, and setting up the closer for the final inning(s). Their ability to perform effectively in high-pressure situations and get crucial outs greatly impacts their team’s chances of winning.

Can Closers Be Setup Pitchers?

Yes, it is possible for closers to also serve as setup pitchers in certain situations. While the traditional role of a closer is to pitch the final inning(s) and secure the victory, managers may choose to utilize their best relief pitcher in high-leverage situations earlier in the game.

Here are a few scenarios where a closer may be used as a setup pitcher:

Extra-Inning Games

If a game goes into extra innings and the closer’s team needs to keep the game tied or prevent the opposing team from taking the lead, the manager may bring in the closer earlier than usual. The closer’s ability to pitch effectively in high-pressure situations makes them a valuable asset in these critical moments.

Key Matchups

If there is a critical juncture in the middle or late innings where the opposition’s best hitters are due up, the manager may choose to bring in the closer to face those batters. This strategy allows the team to maximize the closer’s talent and increase the likelihood of getting important outs.

Unavailability of Other Setup Options

There may be situations where the team’s designated setup pitchers are unavailable due to workload, rest, or injury. In such cases, the closer, who is often one of the most talented and reliable pitchers in the bullpen, may be called upon to fill the setup role temporarily.

Playoffs or High-Stakes Games

In postseason games or crucial matchups where the outcome has significant implications, managers may be more inclined to use their best reliever, including the closer, in situations that deviate from the traditional roles. The focus is on maximizing the team’s chances of winning in critical moments.

It’s important to note that not all closers will be used as setup pitchers regularly, as teams typically assign specific pitchers to designated roles based on their strengths, workload management, and overall bullpen strategy. 

However, in certain circumstances, closers may indeed be utilized as setup pitchers to address specific game situations or to provide an extra boost to the team’s bullpen.


Why is the setup pitcher called “SU”?

The abbreviation “SU” for the setup pitcher is derived from the term “setup man.” It is a shortened form of the word to make it more convenient and easier to display on scoreboards, in game recaps, and during broadcasts. 

How does the setup pitcher differ from the closer?

While the setup pitcher’s primary responsibility is to pitch in the eighth inning and prepare the way for the closer, the closer’s role is to pitch in the ninth inning and secure the victory. 

Are setup pitchers limited to pitching only in the eighth inning?

While the traditional setup pitcher typically enters the game in the eighth inning, the role has evolved in recent years. Some teams now employ multiple setup pitchers and may use them in different innings depending on the game situation, matchups, and workload management. 

What are the key qualities of a successful setup pitcher?

Successful setup pitchers possess several key qualities. They need to have an excellent command of their pitches, the ability to generate strikeouts, induce ground balls and limit walks and hits. They should also be mentally resilient, able to handle high-pressure situations, and perform consistently.

Final Words

So, now you know what SU means in baseball. To summarize, “SU” in baseball stands for the setup pitcher. These are the relief pitchers who enter the game in the eighth inning to bridge the gap between the starting pitcher and the closer.

Their objective is to maintain or extend their team’s lead, setting the stage for the closer to finishing the game in the ninth inning. The setup pitcher’s role requires specific skills, and their contributions are crucial to a team’s success.

As you continue to enjoy America’s favorite pastime, remember to appreciate the efforts of the setup pitchers, whose contributions often go unnoticed but play a vital role in the outcome of the game.

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John Means

John Means is a professional baseball player who has played in the major leagues for the Kansas City Royals and the Oakland Athletics. He made his major league debut with the Royals in 2009. He was traded to the Athletics in 2012. Baseball is his favorite sport. His passion about the game is evident in his play. Now he write blogs about baseball and other things whenever he has some free time. LinkedIn

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