What Is a Bullpen in Baseball?

Seeing batters hit one home run after another is certainly a sight for sore eyes. Want to know what is equally pleasurable to see? Seeing pitchers retiring batters one by one! 

However, retiring batters in such a dominant fashion takes a lot of practice and hours of bullpen sessions.


What is a bullpen in baseball?

A bullpen is baseball lingo for describing an allotted area where pitchers and batters warm up before a game. More often than not, a bullpen area is situated at each side of the outfield. 

Sometimes, the bullpen may even be located in foul territory, along the first base and third base lines.  

The bullpen is also an area in the baseball field where relief pitchers warm up and prepare before entering a game. The relief pitchers use the area to get ready for when they are called upon to pitch innings, in case a starting pitcher exits a game early or a game goes to extra innings. 

Only two pitchers (relievers) are permitted to stay in the bullpen simultaneously during a game. However, bullpen sessions that take place during practice can have as many participants (relievers) as required.

What happens during a bullpen session and what is its importance?

Bullpen practice sessions are expertly utilized by pitchers to work on their craft (pitching abilities). Additionally, the sessions can also be set up to help pitchers with their pitching mechanics, pitch control, pitching grips, throwing mechanics, fielding mechanics, pickoff moves, and mental preparation.

Of course, pitchers donʼt throw with their guns blazing during bullpen practice sessions as the sessions are meant to help the pitchers fine-tune their throws, not overwork their throwing arms.

A bullpen session, on average, usually lasts anywhere between 15 to 20 minutes, with a pitcher not throwing more than 50 pitches off a mound. Of course, if a starting pitcher has pitched extensively in a previous game, he wonʼt put in an extensive workout.

Without frequent sessions in the bullpen, both starters and relievers would find it difficult to stay sharp and on top of their game. Without bullpen practice sessions, a pitcher would lose touch with his pitching mechanics as he wouldn’t get the chance to practice his different pitches off the mound. 

Pitchers would also notice a sharp decline in rapport with their catchers. When that happens, it is only a matter of time before they get hit all over the park during baseball games.  

And, as starting pitchers get battered heavily, they are often tempted to over-compensate their throws with extra oomph, resulting in wrong pitch mechanics, which puts extra unwanted stress on their shoulders and elbows that could result in injuries.

How did the term “bullpen” come about in a baseball game?

There are a few theories regarding how the term “bullpen” came about and if you’re really interested, you can look the term up in The New Dickson Baseball Dictionary written by Paul Dickson.

The first theory indicates that the bullpen area (an area for relief pitchers) was once reserved for late-arriving fans who weren’t willing to shell out big bucks for the spectators’ stands in the main arena. And, since the fans there had to watch the game whilst standing in the roped-off area, they were typically viewed as cattle in a field, hence the name “bullpen.”

The second theory suggests that the standing area for fans was described as a “bullpen” because of the area’s close proximity to a Bull Durham Tobacco advertisement affixed to the outfield wall. You see, during that time, almost all baseball fields had the same Bull Durham tobacco advertisement on their outfield fences. 

And, as the same area began developing as a place for a relief pitcher to warm up, and despite the removal of the advertisement, the name still stuck.

There are also some who believe that the term came about because of the pitchers’ likeness to bulls themselves. Those people believed that the pitchers were similar to bucking bulls, soon to be released from the pen for further action in a rodeo.

Lest we forget, there are also people who believe that the bullpen represents the fenced-in area of a bull’s pen, where the rodeo bulls wait in a makeshift prison before they are sent off to the slaughter, akin to the pitchers simply waiting in line to get battered by the batters. 

Lastly, during the US Civil War, there was the notorious Andersonville prison camp that inmates called a bullpen because it was so jam-packed. Some believe the baseball bullpen was named after this because it was so crowded.

Although we arenʼt quite certain about which theory to believe, we do know for a fact that the term was originally coined by Baseball Magazine in their 1915 article. 

However, the article didnʼt elaborate on why a relief pitcherʼs area is called a bullpen. Therefore, the origin of the word is still up in the air.

Whatʼs a bullpen day?

A bullpen day, also often recognized as a bullpen game, is a game in which teams decide to begin proceedings with their relief pitcher instead of their usual starting pitcher.

During these types of games, the relief pitchers are tasked to pitch for a couple of innings. After that, they make way for the usual starting pitcher. 

Sometimes, there is more than one relief pitcher deployed by a team. This is done to prevent the opposition batters from getting comfortable with the deliveries of the pitchers. 

Teams also usually deploy this strategy to prevent their starting pitchers from burning out in the earlier innings. After all, every team wants their best pitcher to close out games.

Do bull pen sessions guarantee success for the relief pitcher on the field?

Though relief pitching is fundamental to the sport, it doesn’t guarantee success on the field. For a pitcher (both starters and relievers) to notice considerable growth in his speed of the pitch, he must partake in strength and cardio training workouts that complement his bullpen practice sessions. 

In the competitive world of modern baseball, every extra mile per hour on a pitch can be the deciding factor between success and failure.


In conclusion, the bullpen in baseball is an area where both relief pitchers and starters warm up before a game. This area is also extensively used by the players to improve their craft. 

In essence, bullpens exist primarily to bring the best out of a pitcher. Hence, bullpen practice sessions are instrumental in determining the success of a team.