Types of Pitchers in Baseball: SP, RP, and CP Explained

The sport of baseball has many different acronyms. While there are some very common acronyms that get used by spectators, players, and coaches, there are also some uncommon acronyms that might sound new to people. Although with the popularity of fantasy baseball and video games, like MLB The Show, these uncommon acronyms have been getting used more often. Three of those acronyms you usually see lumped together are SP, RP, and CP. What does SP, RP, and CP mean in baseball?

In baseball, SP, RP, and CP are acronyms for different types of pitchers. SP stands for Starting Pitcher, RP stands for Relief Pitcher, and CP stands for Closing Pitcher.

Even though a team can throw one pitcher at a time, the pitcher position is unique because it can have different categories of pitchers for different scenarios in a game.

SP, RP, and CP Explained

When discussing defensive strategy in baseball, there is nothing more important than the pitching strategy. A team’s pitching strategy can make or break a game so a lot of effort is dedicated towards the best way to utilize a bullpen.

Because of the importance of pitching strategies, baseball has naturally broken down the one overall pitcher position into many types of pitchers. Let’s review three of those types of pitchers: SP, RP, and CP.

Starting Pitchers (SP) Are the First Pitchers in a Game

Each game needs to start off with one player in the pitcher’s position. The pitchers who start the game on the mound have the label of SP. What does SP stand for in baseball? What position is SP in baseball?

In baseball, SP stands for Starting Pitcher. A Starting Pitcher is a specific type of pitcher who begins a game in the pitcher’s position, and this role is generally reserved for 4 or 5 players on a team.

Starting pitchers are also expected to throw for 6 or more innings per game. The better a starting pitcher is performing, the longer they stay in the game.

The role of the starting pitcher is to limit the number of runs the opposing team scores, which helps give their team a chance to score some runs and take the lead. If a starting pitcher is having trouble on the mound, a manager will replace that pitcher with a relief pitcher.

Relief Pitchers (RP) Replace the Current Pitcher

Every team needs to be prepared to replace their current pitcher for any reason. Whenever another player enters the pitcher’s position to replace a pitcher, they have the label of RP. What does RP mean in baseball? What position is RP in baseball?

In baseball, RP stands for Relief Pitcher. A Relief Pitcher is a specific type of pitcher who comes into the game to pitch by replacing the current pitcher. A team will usually have between 9-13 players on a roster who are considered a Relief Pitcher.

Depending on the situation of the game, relief pitchers are expected to pitch somewhere between one and five innings. Sometimes they may pitch for more than five innings if the starting pitcher needed to be replaced early in the game, but relief pitchers do not typically pitch for more than five innings in a game.

Even though there are usually between 9-13 relief pitchers on a team, any player on the roster could be a relief pitcher if they replaced the pitcher.

For example, imagine a player who is currently playing shortstop, but the coach decides to swap the shortstop with the pitcher. In this scenario, that player who used to be the shortstop is now considered to be the relief pitcher because they came in to replace the pitcher.

This example may not be common in a Major League game, but it is a common scenario in other baseball leagues, like Little League.

In addition to a team having multiple relief pitchers, the category of relief pitcher can be broken down into further categories. What are the different types of relief pitchers?

In baseball, the different types of relief pitchers are Set Up Man, Middle Relief Pitcher, Long Relief Pitcher, Left/Right Handed Specialist, and Closer.

Each different type of relief pitcher has its own general rules around what their responsibilities are and when they typically enter a game. We’ll cover the role of the Closer below, but feel free to learn more about the Middle Relief Pitcher, Long Relief Pitcher, and Set Up Man from my other articles.

Closing Pitchers (CP) Are a Special Type of Relief Pitcher

When a team is winning towards the end of the game, a common strategy is to bring in a special type of relief pitcher that has the label of CP. What is CP in baseball? And what position is CP in baseball?

In baseball, CP stands for Closing Pitcher. The CP is a specialized Relief Pitcher who enters the game in the final inning while their team has the lead. Closing Pitchers are generally thought to be the best Relief Pitcher on the team.

When a Closing Pitcher performs their job correctly, they earn a Save. The best closing pitchers have the most saves on the team because their team consistently relies on the closing pitcher to “close out” the game and keep the lead.

Most Closing Pitchers pitch for only one inning. This leads a lot of people to wonder why are there closers in baseball?

In general, baseball has closing pitchers because the defense gets an advantage by bringing in a rested pitcher who specializes in pitching during high-stress situations. Good closing pitchers give their team the best chance to win by pitching in the final inning of a game.

Even though it might seem counter-intuitive to bring in a new pitcher to throw for only three outs, those last three outs of the game can be the toughest three outs to get, especially when the game is on the line.

Closing pitchers also have the advantage of being available to throw for multiple games in a row. Unlike other pitchers, closers are only needed for three outs each time they pitch so they are more likely to be rested and ready to pitch multiple days in a row.

Closing pitchers are typically the best relief pitcher on the team and having your best relief pitcher available for multiple days in a row can lead to the team getting more wins.