A couple days ago, a baseball neophyte friend of mine asked me, “In baseball, what is a closer?”  And as I explained the concept, it occurred to me that I haven’t done one of these posts in awhile.

In baseball, a closing pitcher, more commonly referred to as a closer, is a relief pitcher who typically enters the game in the final inning.  Ideally, the closer’s team will be leading on the scoreboard at that point, and so the closer’s job is to “close” the game, getting the final outs of that final inning.

A closer’s effectiveness has traditionally been measured by the number of saves he earns.  A save is a statistic credited to a relief pitcher, as set forth in Rule 9.19 of the Official Rules of Major League Baseball.  The rule states that the official scorer shall credit a pitcher with a save when that pitcher meets all four of the following conditions:

1. He is the finishing pitcher in a game won by his team;
2. He is not the winning pitcher;
3. He is credited with at least ⅓ of an inning pitched; and
4. He satisfies one of the following conditions:
   1. He enters the game with a lead of no more than three runs and pitches for at least one inning
   2. He enters the game, regardless of the count, with the potential tying run either on base, at bat or on deck
   3. He pitches for at least three innings.

Over time, closers have become one-inning specialists typically brought in at the beginning of the ninth inning in save situations.  They enter the game facing the high pressure that comes with having to seal those last three outs and, thus, a win for their club, which makes their role a rather essential one to a team’s success.

Mariano Rivera is MLB’s all-time leader in regular season saves with 652.