Adam Wainwright, currently a starter for the St. Louis Cardinals, started out in the bullpen and was the closer when they won the 2006 World Series. (Image via flickr.com user bk1bennett.)

At a Rangers game recently, a friend of mine asked why are some guys starting pitchers and why are others relief pitchers.  Well, like most things in baseball, there’s not really a simple answer.

In the past, relief pitchers were really just ex-starters or guys who just weren’t cut out to be a starter.  Now, it’s not quite as clear cut.

Typically, a starting pitcher (the guy who starts out pitching in a game) is capable of pitching 5+ innings.  He also usually has 3 or more different types of pitches, such as a curve ball or a fast ball, that he has pretty decent command of.  Since most teams have 5 starting pitchers (also known as the rotation), a starter will only pitch in a game every 5 days.

It varies by game, but generally a starting pitcher is taken out 1) when he starts sucking, 2) when he appears fatigued, 3) he gets injured or 4) he has reached his pitch count (the number of pitches he has thrown during the game).  On average, a starting pitcher’s maximum pitch count is about 100 pitches.  Obviously, pitchers have pitched more than that, but that’s the magic number for most.

A relief pitcher, on the other hand, could very well pitch several days in a row, but typically only an inning, but a reliever typically only has 2 good types of pitches.  Over time, the role of the relief pitcher has become more and more specific.  Most bullpens (the roster of relief pitchers on the team) are composed of various types of relief pitchers.  The most widely known guy is the closer.

The closer is the guy called on to finish out the game.  He typically comes in in the 9th inning when his team has the lead.  In order to be considered a “save” (the stat that most closers are judged on), the closer’s team needs to win the game by  no more than 3 runs and he got at least one of the final outs.  (As is the case in most baseball things, a save is a little more complicated than that, but that’s the typical definition.)  In most cases, if the team is ahead by more than 3 runs, the manager would not bring in his closer and would use one of his other relief pitchers.

Most bullpens also have:

• Set-up pitcher – the guy who comes in the 8th inning before the closer comes in
• Left-handed specialist (AKA: LOOGY or Lefty One Out GuY)- a guy who only pitches to left-handed batters
• Middle relief pitchers – guys who can pitch in the innings after the starter leaves the game and before the set-up pitcher
• Long reliever – a guy who can pitch several innings should the starter only last a couple of innings

Obviously, these are the general definitions of these pitching roles.  Teams will often use their long relief guys as a starter at times if a starter needs an extra day off or is injured.  There are also games that are considered “bullpen games” where the manager will use several relief pitchers for 1-2 innings throughout the course of a game instead of a starter.

If you have a baseball-related question or topic you’d like to see discussed or explained here, please shoot me an email at LorInBigD@gmail.com or tweet at me @LorInBigD.