Pitch counts are a concern for young pitchers, pitchers recovering from injury, or pitchers who have a history of injuries. The pitcher wants to keep the pitch count low because of his stamina. Often a starting pitcher will be removed from the game after 100 pitches, regardless of the actual number of innings pitched, as it is reckoned to be the maximum optimal pitch count for a starting pitcher. Pitch counts are sometimes less of a concern for veteran pitchers, who after years of conditioning are often able to pitch deeper into games. A pitcher's size, stature, athleticism, and pitches style (and/or type of pitch thrown) can also play a role in how many pitches a pitcher can throw in a single game while maintaining effectiveness and without risking injury.
Pitch count can also be used to gauge the effectiveness of a pitcher. It is better under most circumstances for a pitcher to use the fewest number of pitches possible to get three outs.
Opposing teams also pay attention to pitch counts, and may try to foul off as many pitches as possible (or at least any difficult-to-hit pitches) either to tire the pitcher out, or to inflate the pitch count and drive a pitcher from the game in favor of a possibly less effective relief pitcher.
Opponents of the focus on pitch count have argued that the inclusion of the pitch count has hurt pitchers more than it has protected them. Critics of the pitch count contend that pitchers are "babied" and that many of the injuries that pitchers have suffered since the inclusion of the pitch count are from such treatment. Advocates who are against the pitch count include former Florida Marlins manager Jack McKeon, and Texas Rangers President/Hall of Famer Nolan Ryan. McKeon openly told his pitchers (and the media) that he did not keep a pitch count, and that he expected his pitchers to get into the mindset of completing what they started (i.e., for his starters to pitch a complete game). Ryan's sentiments are similar to McKeon's, declaring that pitch counts are largely frivolous. Bruce Jenkins has suggested that a "relief" (i.e. lesser) pitcher should start the game, so that the "starting" (i.e. stronger) pitcher would play the more crucial later innings.
Through the 1960s, it was common for the starting pitcher to pitch a complete game. Comparisons with the dead-ball era pre-1920 are misleading, since the pitcher's behavior was very different. In a 26-inning game on 1 May 1920 where Leon Cadore of Brooklyn and Joe Oeschger of Boston pitched an estimated 345 and 319 pitches. Nolan Ryan threw 259 pitches in 12 innings against Kansas City in 1974, and 162 in a 1989 game, aged 42. Stats LLC began tracking pitch counts in 1988, and MLB keeps official data since 1999. The highest pitch count since 1990 is 166, by David Cone for the New York Mets against the San Francisco Giants on July 17, 1992; years of such abuse may have led to the aneurysm which developed in Cone's right armpit in 1996, threatening his career. Pitch counts above 125 are increasingly rare:
- Basic pitch count estimator: used to try to estimate the number of pitches thrown by a pitcher where there is no pitch count data available
- ↑ Rany Jazayerli, "Baseball Prospectus Basics: How We Measure Pitcher Usage," BaseballProspectus.com (March 3, 2004).
- ↑  A statistic labeled PAP (Pitcher Abuse Points) developed by Rany Jazayerli of Baseball Prospectus in 1998 set such an absolute cut-point of 100 pitches, below which there was no pitcher abuse (overuse) but above which one abuse point was added for each 10 additional pitches. Later, however, Jazayerli conceded PAP to a more sensitive measure, called PAP3 developed by Keith Woolner and first published in the Baseball Prospectus 2001 annual volume. In an article in that same volume, Jazayerli declared: "PAP is dead. Long live PAP3." PAP3 was more highly predictive of declines in pitcher endurance and the risk of breakdowns than the original PAP measure. PAP3 still takes 100 pitches as a reference point but penalizes use above that point as a cubic function of the number of pitches above that level.
- ↑ 3.0 3.1 Brown, Tim. "No victor in Rays-Rangers culture clash". Yahoo! Sports. April 30, 2009.
- ↑ 4.0 4.1 4.2 4.3 Jenkins, Bruce. "Let them learn to pitch and learn to finish", San Francisco Chronicle, August 27, 2008. Retrieved on 2009-03-25.
- ↑ 5.0 5.1 Passan, Jeff (27 Apr 2008). Count on it. Yahoo! Sports. Retrieved on 2009-03-25.
- ↑ It is believed that the fewest number of pitched thrown in one complete 9-inning game is 58, by Red Barrettof the Boston Braves vs. the Cincinnati Reds (in Cincinnati) on August 10, 1944. Barrett faced the minimum 27 batters, allowing 2 hits, while neither walking not striking out a batter. Markusen, Bruce (2007-11-11). Card Corner--Who Is Mike Harkey?. Bronx Banter. Retrieved on 2009-03-25.
- Jazayerli, Rany. 1998. "Pitcher Abuse Points: A New Way to Measure Pitcher Abuse," BaseballProspectus.com (June 19).
- Jazayerli, Rany. 1999. "Pitcher Abuse Points - One Year Later: A Look Back...and Ahead," BaseballProspectus.com (May 28).
- Jazayerli, Rany. 2001. "Rethinking Pitcher Abuse," Baseball Prospectus 2001 (Dulles, VA: Brassey's): 491-504.
- Woolner, Keith, and Rany Jazayerli. 2001. "Analyzing PAP," Baseball Prospectus 2001 (Dulles, VA: Brassey's): 505-516.
- Woolner, Keith. 2002. "PAP3 FAQ," BaseballProspectus.com (June 5).