Baseball statistics refers to a variety of metrics used to evaluate player and team performance in the game of baseball.
In baseball, an at bat (AB) or time at bat is a batter's turn batting against a pitcher. An at bat is different from a plate appearance. A batter is credited with a plate appearance regardless of what happens during their turn at bat, but a batter is charged with an at bat only if that plate appearance does not have one of the results enumerated below. While at bats are used to calculate certain statistics, including batting average and slugging percentage, a player can qualify for the season-ending rankings in these categories only if they accumulate 502 plate appearances during the season.
In baseball, an earned run is any run that was fully enabled by the offensive team's production in the face of competent play from the defensive team. Conversely, an unearned run is a run that would not have been scored without the aid of an error or a passed ball committed by the defense.
A base on balls (BB), better known as a walk occurs in baseball when a batter receives four pitches during a plate appearance that the umpire calls balls, and is in turn awarded first base without the possibility of being called out. The base on balls is defined in Section 2.00 of baseball's Official Rules, and further detail is given in 6.08(a). Despite being known as a "walk", it is considered a faux pas for a professional player to actually walk to first base; the batter-runner and any advancing runners normally jog on such a play.
In baseball statistics, a hit, also called a base hit, is credited to a batter when the batter safely reaches or passes first base after hitting the ball into fair territory with neither the benefit of an error nor a fielder's choice.
In baseball, a stolen base occurs when a runner advances to a base unaided by other actions and the official scorer rules that the advance should be credited to the action of the runner. The umpires determine whether the runner is safe or out at the next base, but the official scorer rules on the question of credit or blame for the advance under Rule 10 of the MLB's Official Rules.
Baseball is a bat-and-ball sport played between two teams of nine players each, taking turns batting and fielding. The game occurs over the course of several plays, with each play generally beginning when a player on the fielding team, called the pitcher, throws a ball that a player on the batting team, called the batter, tries to hit with a bat. The objective of the offensive team is to hit the ball into the field of play, away from the other team's players, allowing its players to run the bases, having them advance counter-clockwise around four bases to score what are called "runs". The objective of the defensive team is to prevent batters from becoming runners, and to prevent runners' advance around the bases. A run is scored when a runner legally advances around the bases in order and touches home plate.
In baseball, a home run is scored when the ball is hit in such a way that the batter is able to circle the bases and reach home plate safely in one play without any errors being committed by the defensive team. A home run is usually achieved by hitting the ball over the outfield fence between the foul poles without the ball touching the field.
In baseball, the strike zone is the volume of space through which a pitch must pass in order to be called a strike even if the batter does not swing. The strike zone is defined as the volume of space above home plate and between the batter's knees and the midpoint of their torso. Whether a pitch passes through the zone is decided by an umpire, who is generally positioned behind the catcher.
Softball is a sport similar to baseball, and it is played with a larger ball on a smaller field and with only underhand pitches permitted. Softball is played competitively at club levels, the college level, and the professional level. The game was first created in 1887 in Chicago by George Hancock.
In baseball, a wild pitch (WP) is charged against a pitcher when his pitch is too high, too short, or too wide of home plate for the catcher to control with ordinary effort, thereby allowing a baserunner, or the batter, to advance.
In baseball or softball, a strikeout occurs when a batter accumulates three strikes during a time at bat. It usually means that the batter is out. A strikeout is a statistic recorded for both pitchers and batters, and is denoted by K in scorekeeping and statistics. A "strikeout looking"—in which the batter does not swing and the third strike is called by the umpire—is usually denoted by a Ʞ.
In baseball and softball statistics, an error is an act, in the judgment of the official scorer, of a fielder misplaying a ball in a manner that allows a batter or baserunner to advance one or more bases or allows a plate appearance to continue after the batter should have been put out. The term error is sometimes used to refer to the play during which an error was committed.
In baseball, an intentional base on balls, usually referred to as an intentional walk and denoted in baseball scorekeeping by IBB, is a walk issued to a batter by a pitcher with the intent of removing the batter's opportunity to swing at the pitched ball. A pitch that is intentionally thrown far outside the strike zone for this purpose is referred to as an intentional ball.
In baseball and softball, the count refers to the number of balls and strikes a batter has in their current plate appearance. If the count reaches three strikes, the batter strikes out; if the count reaches four balls, the batter earns a base on balls.
Throughout the history of baseball, the rules have frequently changed as the game continues to evolve. A few common rules most professional leagues have in common is that four balls is a base on balls, three strikes is a strikeout, and three outs end a half-inning.
In baseball, a pitcher can commit illegal motions or actions that constitute a balk. Most of these violations involve pitchers pretending to pitch when they have no intention of doing so. In games played under the Official Baseball Rules that govern professional play in the United States and Canada, a balk results in a dead ball or delayed dead ball. In certain other circumstances, a balk may be wholly or partially disregarded. In the United States, under the National Federation of State High School Associations, a balk results in an immediate dead ball. In the event a balk is enforced, the pitch is generally nullified, each runner is awarded one base, and the batter (generally) remains at bat with the previous count. The balk rule in Major League Baseball was introduced in 1898.
This is an alphabetical list of selected unofficial and specialized terms, phrases, and other jargon used in baseball, along with their definitions, including illustrative examples for many entries.
In baseball statistics, earned run average (ERA) is the average of earned runs allowed by a pitcher per nine innings pitched. It is determined by dividing the number of earned runs allowed by the number of innings pitched and multiplying by nine. Thus, a lower ERA is better. Runs resulting from passed balls, defensive errors, and runners placed on base at the start of extra innings are recorded as unearned runs and omitted from ERA calculations.
