- Ace: The best starting pitcher on a team.
- Alley: The area between the outfielders.
- Around the Horn: Throwing the ball around the infield after an out.
- Assist: Credited to a player who throws or deflects the ball to another player in a play that results in an out.
- At-bat (AB): An official turn to bat, excluding walks and sacrifices.
- At Bat: A player’s turn batting.
- Backstop: The fence/wall behind home plate.
- Bag: Another term for base.
- Balk: Illegal motion by a pitcher.
- Ball: A pitch outside the strike zone.
- Bases Loaded: Runners on all three bases.
- Batting Average (BA): A statistic that represents the number of hits divided by at-bats.
- Bench Coach: Assistant to the manager.
- Bloop: A weakly hit fly ball.
- Bullpen: Area where pitchers warm up.
- Bunt: Tapping the ball lightly.
- Changeup: A slow pitch.
- Closer: Pitcher who finishes games.
- Count: The number of balls and strikes.
- Curveball: A breaking pitch with a downward movement.
- Cut-Off Man: Infielder who relays throws.
- Designated Hitter (DH): A player who bats in place of the pitcher in the American League.
- Double: A two-base hit.
- Double Play: Two outs on one play.
- Dugout: Team’s bench area.
- Earned Run: Run for which pitcher is responsible.
- Earned Run Average (ERA): Average number of earned runs allowed by a pitcher per nine innings.
- Error: A mistake in fielding that allows a batter or runner to advance.
- Extra Bases: Hits other than singles.
- Extra Innings: Innings played after the ninth to break a tie.
- Fair Ball: A ball in play within boundaries.
- Fastball: A pitch thrown at high speed, often the pitcher’s fastest.
- Fielder’s Choice: A play where a fielder chooses to put out a different runner than the batter.
- Fly Ball: A ball hit high into the air.
- Force Out: Out made by stepping on a base.
- Foul Ball: A ball hit outside the boundary lines.
- Foul Tip: A ball that goes sharply to the catcher’s mitt.
- Glove: The leather hand covering for fielding.
- Go-Ahead Run: Run that puts a team in the lead.
- Grand Slam: Home run with bases loaded.
- Ground Ball: Ball hit on the ground.
- Hit (H): Successfully reaching base because of a batted ball.
- Hit and Run: Runner starts as the pitch is thrown.
- Hit By Pitch (HBP): A batter reaching base because of being hit by a pitch.
- Home Plate: The plate a batter stands beside.
- Home Run (HR): A hit that allows the batter to circle all bases and score.
- Infield: The area within the four bases; also, The area inside the bases.
- Infield Fly Rule: Rule for pop-ups with runners on base.
- Infielder: A player who fields in the infield.
- Inning: A segment of the game in which both teams have a turn to bat; also, A segment of the game.
- Intentional Walk: A deliberate base on balls to avoid pitching to a strong batter.
- Juiced Ball: Informal term for a baseball suspected of being designed to increase home runs; also, A livelier, more bouncy baseball.
- Jump: A quick move by a baserunner attempting to steal.
- Lead Off: The first batter in an inning.
- Leadoff Batter: The first batter in a team’s lineup.
- Left Field: The outfield area to the left.
- Left on Base (LOB): Runners who are still on base when an inning ends.
- Line Drive: A ball hit sharply and directly in the air; also, A ball hit straight and hard.
- Lineup: The batting order.
- Minor League: Professional leagues below the Major League level.
- Mound: The raised area in the center of the diamond where the pitcher stands; also, The pitcher’s area.
- MVP (Most Valuable Player): An award given to the best player in the league.
- No-hitter: A game in which a pitcher allows no hits.
- No-Decision: A starter not involved in the decision.
- Nubber: A weakly hit ball.
- On-Base Percentage (OBP): A measure of how often a batter reaches base.
- On-Deck: Next batter due.
- Out: The result of a defensive play that removes a batter or runner from play; also, When the offensive player is removed from play.
- Outfield: The area beyond the infield.
- Outfielder: Player who covers the outfield.
- Passed Ball: A catcher misses a pitch.
- Perfect Game: No batter reaches base.
- Pinch Hitter: A substitute batter.
- Pinch Runner: Substitute runner.
- Pitch: The act of throwing the ball to the batter.
- Pitch Count: The number of pitches thrown by a pitcher.
- Pitcher: Player who pitches the ball.
- Play Ball: Umpire’s call to start.
- Pop Fly: A ball hit high into the air in the infield; also, A high, short fly ball.
- Position Player: A non-pitcher player.
- Quality Start: A start by a pitcher lasting at least six innings with three or fewer earned runs.
- Quick Count: When a pitcher works with a limited number of warm-up pitches; also, A situation where a batter quickly has two strikes.
- RBI (Runs Batted In): The number of runs a batter generates through hits, walks, or sacrifices; also, Number of runners a player has batted in.
- Relief Pitcher: A pitcher who comes into the game after the starting pitcher; also, A pitcher who comes in relief.
- Rookie: A first-year player.
- Run: A score made by a player who reaches home plate; also, The score in baseball.
- Runner: A player on base.
- Sacrifice Fly: Fly ball that scores a run.
- Sacrifice Hit: A batter’s deliberate act of making an out to advance a runner; also, Bunt that advances a runner.
- Save: Preserving a lead by a relief pitcher.
- Scoring Position: Runner on second or third base.
- Shortstop: Infielder between second and third base.
- Shutout: Game where one team doesn’t score.
- Single: A one-base hit.
- Slider: A pitch that breaks laterally.
- Splitter: A pitch that suddenly drops.
- Starter: The first pitcher in the game.
- Stolen Base: A base taken by a runner during a pitch.
- Strike: A pitch within the strike zone.
- Strikeout: Three strikes against a batter.
- Substitute: Player who replaces another.
- Tag: Touching a runner with the ball for an out.
- Tag Up: Runner returns to base after a catch.
- Triple: A three-base hit.
- Triple Play: Three outs on one play.
- Two-bagger: Another term for a double.
- Umpire: Official who enforces the rules; also, The game’s official.
- Unassisted Play: An out made without a throw.
- Utility Player: Player who can play multiple positions.
- Visiting Team: The team playing away from its home field.
- Walk: A base on balls.
- Walk-Off Hit: A game-ending hit by the home team.
- Warning Track: The area near the outfield wall.
- Wild Pitch: A pitch too difficult for the catcher to control.
- Win (W): Credited to the pitcher whose team takes a lead while he is pitching and maintains it.
- Winning Pitcher: The pitcher who was in the game when his team took the lead for good.
- Yakker: Slang for a big, breaking curveball.
- Zone: The strike zone.
- Zone Play: Defensive strategy focusing on covering specific areas.