Innings pitched

In baseball, innings pitched (IP) are the number of innings a pitcher has completed, measured by the number of batters and baserunners that are put out while the pitcher is on the pitching mound 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 34 13 innings, 72 23 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.


The only active players in the top 100 all-time at the end of the 2009 season were Tom Glavine (ranked 30th with 4,413 13 IP), Randy Johnson (ranked 38th with 4,135 13), Jamie Moyer (ranked 45th with 3,908 23) and John Smoltz (ranked 74th with 3473). This is because over time, innings pitched has declined. Several factors are responsible for this decline:

  • From 1876–1892, 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 376 23 innings in 1972 and then 359 13 innings in 1973.
  • 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 bullpens more and more, accelerating the decline in innings pitched. Today, rarely more than a few pitchers pitch more than 250 innings in a season.


All-time leaders

RankPlayerInnings pitched
1Cy Young7,356
2Pud Galvin6,003 13
3Walter Johnson5,914 13
4Phil Niekro5,404
5Nolan Ryan5,386
6Gaylord Perry5,350
7Don Sutton5,282 13
8Warren Spahn *5,243 23
9Steve Carlton *5,217 23
10Grover Cleveland Alexander5,190
11Kid Nichols5,067 13
12Tim Keefe5,049 23
13Greg Maddux5,008 13
14Bert Blyleven4,970
15Bobby Mathews4,956
16Roger Clemens4,916 23
17Mickey Welch4,802
18Christy Mathewson4,788 23
19Tom Seaver4,783
20Tommy John *4,710 13
* Pitched left-handed
Active players in bold
Through 2016 season

Single season leaders

Per Baseball Reference:[1]

RankPlayerYearTeamInnings pitched
1Ed Walsh1908Chicago White Sox464
2Jack Chesbro1904New York Highlanders454 23
3Joe McGinnity1903New York Giants434
4Ed Walsh1907Chicago White Sox422 13
5Vic Willis1902Boston Beaneaters410
6Joe McGinnity1904New York Giants408
7Ed Walsh1912Chicago White Sox393
8Dave Davenport1915St. Louis Terriers392 23
9Christy Mathewson1908New York Giants390 23
10Jack Powell1904New York Highlanders390 13


  1. "Pitching Season Finder (Single seasons, IP>=390)". Baseball Reference. Retrieved July 28, 2017.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.