As we continue our “back to the basics” series, we thought we’d offer a list of the most common terms and jargon in baseball. It’s always good to make sure you know all of the rules and definitions of the game.
If you’re just getting into the game, start with our general information. It will give you the basics that you need to know.

As you develop more knowledge, you can move on to some of the nuances of the game. As someone who has been playing for over 25 years, some of the statistics can still be difficult to remember.
A
Assist
When a defensive player throws a runner out.
At Bat
When the batter comes to the plate and either gets on base through a hit or error or gets out through any means other than a sacrifice.
Note: a walk, sacrifice fly, or sacrifice bunt does not count as an at bat.
B
Ball
When a pitch is thrown outside of the strike zone.
Balk
When the pitcher makes an illegal pitching motion. The result of a balk is that all runners are given the next base.
Base Hit
When the ball is put into play and the base runner reaches bases safely.
Note: Some people will use a base hit to refer to any hit, but most commonly a base hit is used as a synonym for a single.
Bases Loaded
When there is a runner on every base.
Batter’s Box
The area that a batter must stand inside of. It is typically 6 feet long and 4 feet wide.
Batting Average
A way to calculate a batter’s hitting ability. It is the total number of hits divided by the total number of at bats.
Example: A batter who is 1-10 would have a .100 or “one hundred” batting average.
Bullpen
Typically a term reserved for professional players. The bullpen is the area where the relief pitchers sit during the game.
Bullpen can also mean the collective group of relief pitchers on the team.
Bunt
When a player holds the bat in the strike zone and tries to “tap” the ball rather than trying to swing and hit it.
C
Catcher
The player who is positioned behind home plate and attempts to catch pitches thrown by the pitcher.
Catcher’s Interference
When a catcher’s mitt is hit by the batter while swinging at a pitch. Typically, the batter is awarded first base.
Check Swing
When a batter starts to swing, then tries to stop the bat before it crosses the strike zone. If the bat crosses the front of home plate, it is considered a full swing and results in a strike.
If the batter is able to stop his swing before crossing the front of home plate, it is not considered a swing and the pitch is called based on where it was located in the strike zone.
Choke Up
When a batter holds the bat 2-3 inches above the end of the handle.
Coming Set
The point where a pitcher brings his hands together and stops all movement momentarily. Not coming to a full stop when a pitcher is “coming set” can be considered a balk.
Cycle (hitting for the cycle)
When a hitter is able to get a single, double, triple, and home run in one game.
D
Dead Ball
When the ball is no longer “in play” it is considered dead. This means that a player can not advance to the next base or be tagged out. An umpire must make the ball “live” again before the next pitch.
Donut
A piece of equipment used to warm up while a batter is on deck. It is a weight that slides down the bat to the barrel.
Using a donut makes the bat feel heavier during warm ups.
Double
When the ball is hit and the batter reaches 2nd base without an error occurring.
Double Play
When the ball is put into play and two outs are made during that play.
Dugout
The area designated for each team during a game.
E
Earned Run
When a run is scored and the runner reached base without an error occurring.
Some official scorers will also consider how many outs there were when an error occurred.
Error
A defensive mistake that allows runners to reach base or advance an extra bases.
Extra-Base Hit
When the batter puts the ball in play and safely reaches second, third, or home.
Extra Innings
When the game is tied after 9 innings, teams continue playing. The rest of the game after 9 innings is called “extra innings”.
This is baseball’s version of overtime.
F
Fair Ball
A ball that lands on or inside of the foul lines.
Fielder’s Choice
When a defender catches a ground ball and throws out a base runner, but not the batter.
This can also be the result when a defensive player tries to turn a double play, but can’t get the runner out at first.
Fielding Percentage
This is a statistic that measures how often the defensive player successfully completes a play. It is the number of successful plays divided by the number of opportunities.
It is essentially the same calculation as a batting average, but done for a fielder.
Forced Runner
When a runner is on base and every base behind him has a runner on it, the runner is “forced” to move to the next base.
This is also the case for a runner on first.
Force Out
When a defender tags the base that a runner is forced to go to, it is a force out. There is no need to tag the runner.
Foul Tip
When a batter makes contact and the ball goes straight down or straight back to the catcher.
Full Count
When the count is 3 balls and 2 strikes.
G
Grand Slam
A homerun when there is a runner on every base.
Ground Rule Double
When the ball is struck, lands fair, and then bounces out of play. This is most commonly a ball that hits the warning track and bounces over the outfield fence.
Ground Out
When the ball is hit on the ground and the fielder is able to catch the ball and throw the batter out at first base.
H
Hit and Run
A play where the coach allows the hitter to try to hit the ball while also having the runner tries to steal the next base.
Hit by Pitch
When the pitcher throws the ball and the pitch strikes the batter.
Home Run
When the batter hits a ball that goes over the fence. A home run can also occur when the ball rolls away from a fielder and the batter is able to round the bases without getting tagged out.
I
Infielder
A defensive player assigned to player first base, second base, third base, or short stop.
Infield Fly
A ball that is popped up on the infield with runners on first and second or the bases loaded.
This rule prevents the defense from allowing the ball to drop in order to turn a double play.
Intentional Walk
When a pitcher intentionally receives 4 balls.
In Major League Baseball, teams are now allowed to call for an intentional walk and allow the batter to take first base without throwing a pitch.
K
K
Shorthand for strikeout.
L
Left on Base
The runners who were on base when the third out of an inning is recorded.
M
Mound Visit
When the coach or pitching coats comes out to talk to the pitcher.
N
No-Hitter
When a pitcher or group of pitchers finishes the game without allowing any hits.
O
On-Base Percentage
Dividing the number of times on base (Hit + Walk + Hit By Pitch) by the total number of plate appearances.
Outfield
A defensive player assigned to play Left Field, Center Field, or Right Field.
Outfield Assist
When an outfielder throws a runner out at one of the bases.
P
Passed Ball
A pitch that should have been caught, but gets away from the catcher.
This is the most common form of error committed by a catcher.
Perfect Game
When the pitcher or group of pitchers in a game complete that game without allowing a runner to get on base.
Pinch Hitter
When a coach has a new runner take the place of someone who is currently in the lineup and on the base paths.
This is typically done later in the game to gain an advantage.
Pitchout
When a pitcher intentionally throws a ball high and outside with the goal of increasing the odds of a catcher throwing out a base runner.
Plate Appearance
The total number of times that a batter steps to the plate.
This is similar to an at-bat but includes sacrifice plays, walks, and hit by pitches.
Q
Quick Pitch
When a pitcher attempts to pitch before the batter is ready.
Major League Baseball considers this an illegal pitch and qualifies it as a balk.
R
Relief Pitcher
A pitcher who doesn’t start the game.
Run
When a player rounds the bases and touches home.
Run Batted In (RBI)
When a batter puts the ball in play and a runner scores, he is credited with an RBI for every runner that scores.
S
Sacrifice Bunt
When a batter places a bunt with the intent of moving a runner over.
Save
When a relief pitcher comes in to finish and win a game for their team.
A save requires the relief pitcher to enter with a lead that is 3 runs or less or a situation where the runners on base plus the batter plus the batter on deck could take the lead.
Scoring Position
Refers to a runner who is on second or third base.
Shutout
When a pitcher or group of pitchers prevent the opposing team from scoring a run during the entire game.
Squeeze Play
When a batter lays a bunt down with a runner on third base.
The goal is to place the bunt and bring the runner home to score a run.
Strikeout
When a batter with two strikes swings and misses, has a pitch called a strike by the umpire, or foul tips the ball into the catcher’s mitt.
Switch Hitter
A batter who is able to hit as a left-handed batter or a right-handed batter.
T
Tagging Up
When a player returns to the base they were on during a fly ball, then runs to the next base after the ball is caught.
Total Bases
The number of bases earned after a hit.
A single is worth 1 base. A double is worth 2 total bases. A triple is worth 3 total bases. A home run is worth 4 total bases.
U
Umpire
The person responsible for calling balls and strikes, fair and foul, or safe and outs.
Unearned Run
When a player scores a run after reaching base on an error.
W
Walk
When a batter receives 4 pitches and is given a “free pass” to first base.
Walks and Hits Per Inning Pitched (WHIP)
A statistic used to measure how often a pitcher allows runners to reach base.
To calculate, take the total numbers of Hits, Walks, and Batters Hit By Pitch. Divide that total number by the number of innings pitched.
Example: 70 Hits + 30 Walks in 100 Innings would result in a 1.00 WHIP.
Wild Pitch
When a pitch gets passed the catcher and the pitch was so wild that the catcher couldn’t have been expected to catch it.