What is the Difference Between Class A, Double-A, and Triple-A in Minor League Baseball?

Technically speaking, the difference between Class A, Double-A, and Triple-A in Minor League Baseball (MiLB) is skill-level, with Class A baseball for the youngest and lowest-level players, Double-A for the more experienced players, while Triple-A is for the highest skilled players on the cusp of the majors.

But wait, there is more! As with many things, it is a bit more complicated than that. Often, there is more talent in Double-A than in Triple-A baseball! In the following paragraphs, we will explore:

  • The purpose of Class A, Double-A, and Triple-A teams
  • How a player advances through the farm system
  • Other levels of Class A and lower level baseball

Purpose of Class A, Double-A, and Triple-A Teams

Rather than just placing young players in Big Leagues to see if they will succeed, Major League teams train and develop their young talent with their Minor League affiliates, moving them up to higher levels as the player finds success. In this section, we will:

  • Look at the size of active rosters
  • Why different levels exist in the Minor Leagues
  • How much does a player earn in the Minor Leagues?

How many players are on each team?

There are 30 Major League teams and they and they can only have 25 players on their active roster while they can carry 40 total players on their roster. The other players in their organization fill their Minor League rosters. Each Minor League roster also has limits.

According to MiLB.com, the size of the roster varies depending on the level of the team and the time of year. Minor League teams have active and reserve rosters. A reserve roster is similar to the 40-man MLB roster as it includes players on the Injured List and restricted list.

The active roster size at Triple-A and Double-A is 25 players and these levels do not have a reserve roster. In the Class A Advanced and Class A levels, they are allowed 25 players on their active roster and 35 on the reserve roster. Only two players on the active roster at the Class A Advanced level may have six or more years of Minor League service while only two players on the Class A roster may have five or more years of Minor League service.

Why are there different levels in MiLB?

Unlike other major sports in the United States, professional baseball players often need years of training and development before they can perform at the highest level. In other sports, first-round picks are often expected to play for and even lead their franchises their first season, where, in baseball, this would largely be impossible.  

According to MiLB.com, the Minor Leagues are structured so that a player will face increasingly difficult competition as they progress and develop as a player. The Triple-A and Double-A levels are usually where you find the most talented and experienced baseball players.

How much does a player earn in the Minor Leagues?

How much money can a player earn while in the Minor leagues? Once again, we will seek an answer from MiLB.com which states, “Minor League Baseball player contracts are handled by the Major League Baseball office.” The salaries begin at $1,100 per month for the first season of a contract. After that, the contract is open to negotiation.

For MiLB players that are from foreign countries, they are subject to the “Alien Salary Rates” which are mandated by the United State Immigration and Naturalization Service and are different for aliens on visas. All players at each level earn $25 per day for meal money while they are on the road.

After being signed or drafted, players begin their journey as professional baseball players in the Minor Leagues. Obviously making money is still important, but the Minor Leagues largely serve as a training ground for young baseball talent.

Advancing Up the Farm System

What is the age of a player in the lowest level of the Minor Leagues compared to the highest level? According to Fangraphs, in 2012 the average age for professional players at the various Minor League levels was as follows:

  • Triple-A: 28.2
  • Double-A: 23.8
  • Class A: 21.2

It is by no means a rule that Class A players must all be under the age of 22, but this is a good indication of how players move up an organization’s farm system and give evaluators another dimension to consider when evaluating talent. One example is when a team is excited about a 20-year-old player who produces a solid season against Triple-A opponents, almost all of whom are much older.

When does a player stop being a “prospect”?

At a certain point, a player stops being considered a “prospect” even if they are mashing against Triple-A baseball.  They might be simply too old for an organization to put a lot of trust in them contributing to the big-league club, therefore they are no longer seen as a worthwhile investment or prospect.

In the 1988 movie, Bill Durham, a middle-aged Kevin Costner plays a catcher on the verge of the Minor League record for career Home Runs. This is an odious distinction because it means that rather than moving up the ranks of the Minor Leagues and making a big-league roster, Costner has instead spent his prime years, largely considered to be his mid to late 20s, in the Minor Leagues.  As a result, Costner will never make a Major League roster before he retires due to old-age or being released by the club to give playing time to a younger player with more upside in the future.

Levels of Class A and Lower Baseball

There are three different levels of Class A baseball and three different Rookie leagues in the Minor League Baseball system.

Class A Advanced

Class A Advanced is the top level of Class A baseball and is represented by the California League, Carolina League, and the Florida State League. These rosters have 25 active players and typically have players who have been in the Minor League system for at least a year and are close to being ready for Double-A baseball.

Class A

The Midwest and the South Atlantic are the two leagues associated with Class A baseball. This level of baseball has 25 players on their active roster and some players will go directly from college baseball to this level while a player drafted out of high school will rarely begin in this league.

Class A Short-Season

The New York-Penn and the Northwest leagues are the leagues where Class A Short-Season baseball is played. These rosters have 35 active players and no more than three players on their roster with three or more years of MiLB service. This is where most college players will begin after being drafted.

Rookie: Appalachian, Pioneer leagues

These rosters have a limit of 35 active players and a player may not be on the active roster with three or more years of MiLB service. A few of the college players drafted can land in this league along with some advanced high school players.

Rookie: Arizona, Gulf Coast leagues

These leagues have a roster limit of 35 active players and, like the Rookie leagues above, may not have a player on the active roster with more than three years of MiLB experience. This league is typically populated by most of the high school players who were drafted in the June draft.

Rookie: Venezuelan and Dominican Summer leagues

The roster limit for this league is the same as the above leagues with 35 active players. However, no player may be on the active roster with four or more years of MiLB service. These are also excluded from having any draft-eligible player from the United States or Canada. Players from Puerto Rico may participate in these leagues regardless of their draft eligibility.

Related Questions

Why is the Talent in Double-A Baseball Sometimes Better than in Triple-A Baseball?

Sometimes, players skip levels and go from Double-A straight to the Major Leagues if the organization feels that is best for the player or what is needed by the team.  Eventually, players hope to make the Major Leagues as better and more prepared players after making a few stops in the different Minor League levels while teams are continually monitoring their progress at each level.

How Many Players in the Minor Leagues Play in the Major Leagues?

Obviously, not every Minor League player makes the Major Leagues. It is estimated that less than 10% do and some of those players will only be on the active roster for no more than a day or two. The level of competition for Major League Baseball is profound, as evidenced by the sheer number of leagues in place before players get there. Even some Triple-A players do not make the ascent to the next level.