Baseball statistics include a variety of metrics used to evaluate player and team performance in the sport 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.
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.
On-base plus slugging (OPS) is a sabermetric baseball statistic calculated as the sum of a player's on-base percentage and slugging percentage. The ability of a player both to get on base and to hit for power, two important offensive skills, are represented. An OPS of .800 or higher in Major League Baseball puts the player in the upper echelon of hitters. Typically, the league leader in OPS will score near, and sometimes above, the 1.000 mark.
In baseball, a player is credited with a plate appearance each time he completes a turn batting. Under Rule 5.04(c) of the Official Baseball Rules, a player completes a turn batting when he is put out or becomes a runner. This happens when he strikes out or is declared out before reaching first base; or when he reaches first base safely or is awarded first base ; or when he hits a fair ball which causes a preceding runner to be put out for the third out before he himself is put out or reaches first base safely. A very similar baseball statistic, at bats, counts a subset of plate appearances that end under certain circumstances.
Sabermetrics is the original or blanket term for sports analytics, the empirical analysis of baseball, especially the development of advanced metrics based on baseball statistics that measure in-game activity. The term is derived from the movement's progenitors, members of the Society for American Baseball Research (SABR), founded in 1971, and was coined by Bill James, who is one of its pioneers and considered its most prominent advocate and public face.
In baseball statistics, slugging percentage (SLG) is a measure of the batting productivity of a hitter. It is calculated as total bases divided by at-bats, through the following formula, where AB is the number of at-bats for a given player, and 1B, 2B, 3B, and HR are the number of singles, doubles, triples, and home runs, respectively:
A run batted in or runs batted in (RBI) is a statistic in baseball and softball that credits a batter for making a play that allows a run to be scored. For example, if the batter bats a base hit which allows a teammate on a higher base to reach home and so score a run, then the batter gets credited with an RBI.
In baseball, a sacrifice bunt is a batter's act of deliberately bunting the ball, before there are two outs, in a manner that allows a baserunner to advance to another base. The batter is almost always put out, and hence sacrificed, but sometimes reaches base on an error or fielder's choice. In that situation, if runners still advance bases, it is still scored a sacrifice bunt instead of the error or the fielder's choice. Sometimes the batter may safely reach base by simply outrunning the throw to first; this is not scored as a sacrifice bunt but rather a single.
Runs created (RC) is a baseball statistic invented by Bill James to estimate the number of runs a hitter contributes to their team.
Equivalent Average (EqA) is a baseball metric invented by Clay Davenport and intended to express the production of hitters in a context independent of park and league effects. It represents a hitter's productivity using the same scale as batting average. Thus, a hitter with an EqA over .300 is a very good hitter, while a hitter with an EqA of .220 or below is poor. An EqA of .260 is defined as league average.
In baseball statistics, batting average against, also known as opponents' batting average, is a statistic that measures a pitcher's ability to prevent hits during official at bats. It can alternatively be described as the league's hitters' combined batting average against the pitcher.
In baseball, the batting order or batting lineup is the sequence in which the members of the offense take their turns in batting against the pitcher. The batting order is the main component of a team's offensive strategy. In Major League Baseball, the batting order is set by the manager, who before the game begins must present the home plate umpire with two copies of his team's lineup card, a card on which a team's starting batting order is recorded. The home plate umpire keeps one copy of the lineup card of each team, and gives the second copy to the opposing manager. Once the home plate umpire gives the lineup cards to the opposing managers, the batting lineup is final and a manager can make changes only under the Official Baseball Rules governing substitutions. If a team bats out of order, it is a violation of baseball's rules and subject to penalty.
In baseball, fielding independent pitching (FIP) is intended to measure a pitcher's effectiveness based only on statistics that do not involve fielders. These include home runs allowed, strikeouts, hit batters, walks, and, more recently, fly ball percentage, ground ball percentage, and line drive percentage. By focusing on these statistics and ignoring what happens once a ball is put in play, which – on most plays – the pitcher has little control over, DIP claims to offer a clearer picture of the pitcher's true ability.
Walk percentage is a baseball statistic criterion.
Base runs (BsR) is a baseball statistic invented by sabermetrician David Smyth to estimate the number of runs a team "should have" scored given their component offensive statistics, as well as the number of runs a hitter or pitcher creates or allows. It measures essentially the same thing as Bill James' runs created, but as sabermetrician Tom M. Tango points out, base runs models the reality of the run-scoring process "significantly better than any other run estimator".
The 1963 Los Angeles Dodgers were led by pitcher Sandy Koufax, who won both the Cy Young Award and the Most Valuable Player Award. The team went 99–63 to win the National League title by six games over the runner-up St. Louis Cardinals and beat the New York Yankees in four games to win the World Series, marking the first time that the Yankees were ever swept in the postseason.
In baseball, wOBA is a statistic, based on linear weights, designed to measure a player's overall offensive contributions per plate appearance. It is formed from taking the observed run values of various offensive events, dividing by a player's plate appearances, and scaling the result to be on the same scale as on-base percentage. Unlike statistics like OPS, wOBA attempts to assign the proper value for each type of hitting event. It was created by Tom Tango and his coauthors for The Book: Playing the Percentages in Baseball.
On-base plus slugging plus runs batted in (OPSBI) is a baseball statistic calculated as the normalized sum of a player's on-base percentage and slugging percentage added to their runs batted in. Former Major League Baseball general manager, Jim Bowden, created this statistic. Hall of Fame outfielder, Babe Ruth, holds both the single-season and career OPSBI records.
