baseball Baseball is a bat-and-ball sport played between two teams of nine players each, taking turns batting and fielding. The game occurs over the course of several plays, with each play generally beginning when a player on the fielding ...

, innings pitched (IP) are the number of innings a

pitcher In baseball, the pitcher is the player who throws ("pitches") the Baseball (ball), baseball from the pitcher's mound toward the catcher to begin each play, with the goal of out (baseball), retiring a batter (baseball), batter, who attempts to e ...

has completed, measured by the number of

batter Batter or batters may refer to: Common meanings * Batter (cooking), thin dough that can be easily poured into a pan * Batter (baseball), person whose turn it is to face the pitcher * Batter (cricket), a player who is currently batting * Batter ...

s and baserunners that are put out while the pitcher is on the

pitching mound A baseball field, also called a ball field or baseball diamond, is the field upon which the game of baseball is played. The term can also be used as a metonym for a baseball park. The term sandlot is sometimes used, although this usually refers ...

in a game. Three outs made is equal to one inning pitched. One out counts as one-third of an inning, and two outs counts as two-thirds of an inning. Sometimes, the statistic is written 34.1, 72.2, or 91.0, for example, to represent innings, innings, and 91 innings exactly, respectively. Runners left on base by a pitcher are not counted in determining innings pitched. It is possible for a pitcher to enter a game, give up several hits and possibly even several runs, and be removed before achieving any outs, thereby recording a total of zero innings pitched. Alternatively, it is possible for a pitcher to enter a situation where there are two runners on base and no outs. He could throw one pitch that results in a triple play, and for that one pitch he would be credited with a full inning pitched.

Decline

Major League Baseball Major League Baseball (MLB) is a professional baseball organization and the oldest major professional sports league in the world. MLB is composed of 30 total teams, divided equally between the National League (NL) and the American League (AL) ...

, the only active players in the top 100 all-time at the end of the season were Tom Glavine (ranked 30th with IP), Randy Johnson (ranked 38th with ), Jamie Moyer (ranked 45th with ) and John Smoltz (ranked 74th with 3473). By the end of the season, only two active players were in the top 100 all-time: CC Sabathia (ranked 73rd with 3470), and Bartolo Colón (ranked 74th with ). This is because over time, innings pitched has declined. Several factors are responsible for this decline: * From 1876 to 1892, pitchers threw from fifty feet and exerted less stress on their arms (also pitchers often threw underhand in this era). In this era, season totals of 600 innings pitched were not uncommon. * In 1892, pitchers moved back to the current distance of sixty feet, six inches. However, they still often threw 400 innings in a season. This was because the home run was far less common and pitchers often conserved arm strength throughout the game. * From 1920 to the 1980s, the four-man pitching rotation was well established. Pitchers could no longer throw 400 innings in a season, as the home run meant a run could be scored at any time. The league leader in innings pitched often threw somewhat more than 300 innings. Occasionally, innings pitched would spike, as in the early 1970s, when Wilbur Wood pitched innings in and then innings in . * From the 1980s to the present, the four-man rotation was replaced with the five-man rotation, with a weak fifth man who would often be skipped on off days. Also, managers starting using their

bullpen In baseball, the bullpen (or simply the pen) is the area where relief pitchers warm up before entering a game. A team's roster of relief pitchers is also metonymically referred to as "the bullpen". These pitchers usually wait in the bullpen if ...

s more and more, accelerating the decline in innings pitched. As of the start of the 2022 season no pitcher has thrown 250 innings since Justin Verlander in 2011.

Records

All-time leaders

Single-season leaders

Source:

References

External links

Career Leaders & Records for Innings Pitched
at Baseball-Reference.com {{DEFAULTSORT:Innings Pitched Pitching statistics