Baseball has a language of its own. A first game can feel like listening to a conversation in code: the count is full, the runner stole second, the reliever got the save, and the shortstop turned two. This glossary explains the words you will hear most often, grouped by what they describe so you can find them quickly. It is written for new fans, parents of young players and anyone who follows baseball in Europe or elsewhere and wants the vocabulary to feel natural.
Definitions here follow the standard rules of the game. Local leagues, especially youth leagues, can adjust some details, so always check your own league's rulebook. For the official wording of the rules, see the glossary pages published by Major League Baseball and the broader Wikipedia glossary of baseball terms.
The basics of the game
- Inning. One section of the game. Each inning has two halves: the visiting team bats in the top half, and the home team bats in the bottom half. A standard game is nine innings; youth games are often shorter.
- Out. A way for the batting team to lose a turn. Three outs end a half-inning.
- Run. A point. A runner scores by touching first, second, third and home plate in order.
- At-bat. One turn for a batter, not counting walks, hit-by-pitches and sacrifices.
- Dugout. The covered bench area where players wait.
- Bullpen. The area where relief pitchers warm up. The word is also used for a team's group of relievers.
- On-deck circle. The spot where the next batter waits and warms up.
Pitching terms
- Ball. A pitch outside the strike zone that the batter does not swing at. Four balls give the batter a walk.
- Strike. A pitch in the strike zone, a swing and a miss, or a foul ball that comes before two strikes. Three strikes make a strikeout.
- Count. The number of balls and strikes on the batter, always given with balls first. A "full count" is three balls and two strikes.
- Walk (base on balls). The batter takes first base after four balls.
- Strikeout. An out after three strikes.
- Fastball, curveball, slider, changeup. Common pitch types, defined by speed, grip and movement.
- Balk. An illegal move by the pitcher with runners on base. Runners advance one base.
- Wild pitch. A pitch so far off target that the catcher cannot reasonably stop it, allowing runners to move up.
- Passed ball. Similar, but the catcher is judged at fault for not handling a catchable pitch.
- Hit by pitch. The batter is struck by a pitch and takes first base, subject to the rules.
- Starter and reliever. The starter begins the game. Relievers pitch after the starter leaves.
- Closer. A reliever who usually pitches the final inning of a close game.
- Save. A statistic credited to a reliever who finishes a win under defined conditions.
- Shutout. A game in which one team does not score.
- No-hitter and perfect game. A no-hitter is a complete game without allowing a hit. A perfect game means no opposing batter reached base at all.
Hitting terms
- Single, double, triple, home run. Hits that put the batter on first, second, third base or let the batter circle all four bases.
- Grand slam. A home run with the bases loaded, scoring four runs.
- Bunt. A soft, short hit made by holding the bat still, often to move a runner.
- Sacrifice fly. A fly ball caught for an out, but deep enough that a runner tags up and scores.
- Ground ball, fly ball, line drive, pop-up. Descriptions of how the ball was hit: along the ground, in a high arc, flat and hard, or very high and short.
- Foul ball and fair ball. A ball hit inside or outside the foul lines. Fair balls are in play.
- RBI. Run batted in, credited when the batter's action brings a run home.
- Pinch hitter. A substitute batter.
- Walk-off. A hit or play that ends the game in the home team's final turn.
- Batting average. Hits divided by at-bats, usually shown to three decimal places.
Fielding and baserunning terms
- Force out. An out made by touching a base before a runner who must move to it arrives, without having to tag the runner.
- Tag. Touching a runner with the ball or the glove holding the ball.
- Double play. Two outs on one play. A common example is a ground ball to the shortstop who throws to second and then first. See our positions guide for who covers which base.
- Error. A fielding mistake that lets a batter or runner reach or advance when a normal play would have prevented it.
- Fielder's choice. The defense chooses to get another runner out instead of the batter.
- Stolen base. A runner advances while the pitcher is delivering the ball.
- Pickoff. The pitcher or catcher throws to a base to catch a runner leaving too early.
- Tag up. On a fly ball, the runner touches the base after the catch before running.
- Infield fly. A special umpire call that makes the batter out in certain situations; see the full explanation in our infield fly rule guide.
- Bases loaded. A runner on every base.
Statistics you will see on screen
- ERA. Earned run average, a way to measure a pitcher by earned runs allowed per nine innings.
- OBP. On-base percentage, how often a batter reaches base.
- Slugging percentage. A measure of power, using total bases per at-bat.
- WHIP. Walks and hits per inning pitched.
Statistics are shown in many formats, and exact formulas are defined by the leagues that publish them. If you need a precise definition for a scoring decision, use your league's official rulebook.
Words fans and players use casually
Some terms are not in the rulebook. "Frozen rope" is a hard line drive. "Can of corn" is an easy fly ball. A "bleeder" is a weakly hit ball that still finds a gap. "Gas" is a fastball. A "tater" is a home run. The "hot corner" is third base. Fans also say "the Show" for the top level of the sport. These words change from region to region, so you may hear different versions in different countries and leagues.
How to learn the words quickly
- Watch with a scorecard or a scoreboard open. Seeing a term and then hearing it described makes it stick.
- Learn the count first. Balls, strikes and outs explain most of the action.
- Keep the position numbers handy. Many scoring phrases use them; see our positions guide.
- Ask questions. Baseball fans are usually glad to explain.
- Check your league's rules. Youth leagues often change rules, such as pitch counts and mercy rules.
FAQ
What are the most common baseball terms?
The words most often heard in a game are ball, strike, out, inning, run, walk, strikeout, hit, home run, double play and error. Learning the count and the three kinds of outs explains most of what happens.
What does "full count" mean in baseball?
A full count means the batter has three balls and two strikes. The next pitch will either be a walk, a strikeout or a ball in play (or a foul, which keeps the count the same).
What is the difference between a walk and a hit by pitch?
A walk happens after four balls. A hit by pitch happens when the pitcher hits the batter with a pitch that is not swung at, and the batter is awarded first base if the umpire rules that the batter tried to avoid the pitch. Both give the batter first base.
What does ERA mean in baseball?
ERA stands for earned run average. It measures how many earned runs a pitcher allows per nine innings. A lower number is better.
What is a save in baseball?
A save is a statistic credited to a relief pitcher who finishes a close win under defined conditions. The exact conditions are written in the official scoring rules.