Baseball Terms

Below are common baseball terms. Click a term to view its definition.

• Batting Average Batting average is a baseball statistic that measures how often a batter gets a hit, calculated by dividing the number of hits by the number of at-bats.
• Designated Hitter The designated hitter (DH) is a player who bats in place of the pitcher but does not play a defensive position, allowing teams to use a more powerful offensive player without fielding responsibilities.
• Double Play A defensive play in which two offensive players are put out as a result of continuous action.
• Earned Run Average Earned Run Average (ERA) is a baseball pitching statistic that measures the average number of earned runs a pitcher allows per nine innings pitched, and is the primary measure of a pitcher's effectiveness.
• Error (Baseball) An error in baseball is a misplay by a fielder that allows a batter or baserunner to advance when they should have been put out, and affects earned run averages and batting statistics.
• Grand Slam (Baseball) A grand slam is a home run hit with runners on all three bases (bases loaded), scoring four runs — the maximum possible on a single play in baseball.
• No-Hitter A no-hitter is a rare pitching achievement where a pitcher allows no hits to the opposing team throughout a complete game of at least nine innings.
• Perfect Game A perfect game is the rarest pitching achievement in baseball, where a pitcher retires every opposing batter in order across at least nine innings without any batter reaching base for any reason.
• Sacrifice Fly A sacrifice fly is a fly ball out that scores a run when a baserunner tags up and scores from third base after the catch, and does not count against the batter's batting average.
• Stolen Base When a baserunner advances to the next base while the pitcher is delivering the ball to home plate.
• Walk (Baseball) A walk in baseball (base on balls) occurs when a pitcher throws four balls to a batter, who is then awarded first base, and is a key measure of a pitcher's control and a batter's plate discipline.
• Wild Pitch A wild pitch is a pitched ball so far out of the strike zone that the catcher cannot control it, allowing baserunners to advance or a batter to reach base on a third strike.
• Bullpen The area where relief pitchers warm up before entering the game.
• Home Run When a batter hits the ball out of play in fair territory, scoring a run for themselves and any runners on base.
• Strikeout When a batter accumulates three strikes during their at-bat and is out.