This baseball term refers to the number of fastballs a pitcher has thrown in a game. Managers and pitching coaches watch this count because fastballs often add the most wear to a pitcher's arm. If a pitcher throws too many fastballs, he/she may get tired faster and therefore ineffective as he/she wears down. To prevent this, managers and pitching coaches will often put limits on the number of fastballs they want their pitcher to throw in a given inning. For fans, the fastball count helps them stay informed as to how the pitcher is doing in a more general sense. Since one of the most common pitches is the fastball, knowing the fastball count can be especially helpful.
The fastball count is not the only statistic baseball managers and pitching coaches use to monitor fastballs and pitcher fatigue. In addition to how many fastballs a pitcher has thrown, coaches will keep track of how fast the player is throwing them, and in certain cases, how many he or she is throwing per batter. In order to prevent pitcher fatigue, managers and pitching coaches will always track total pitch count. Fastball count, while effective and somewhat easy to track, is not always an effective tool. It should always be used in conjunction with total pitch count.