Earned run average
Encyclopedia
In baseball statistics
, earned run average (ERA) is the mean of earned run
s given up 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. Runs resulting from defensive errors
(including pitchers' defensive errors) are recorded as unearned runs and are not used to determine ERA.
came into vogue in the 1900s. Prior to 1900 – and, in fact, for many years afterward – pitchers were routinely expected to pitch a complete game
, and their win-loss record
was considered sufficient in determining their effectiveness.
Some means had to be found to calculate the apportionment of earned-run responsibility where multiple pitchers assume responsibility in a single game since pitchers have sole responsibility to put opposing batters out. A pitcher is assessed an earned run for each earned run scored by a batter (or pinch-runner) who reached base while batting against that pitcher. After pitchers like James Otis Crandall
and Charlie Hall made names for themselves as relief specialists, gauging a pitcher's effectiveness became more difficult using the traditional method of tabulating wins and losses. The National League
first kept official earned run average statistics in 1912 (the statistic was called "Heydler's statistic" for a while, after then-NL secretary John Heydler
), with the American League
following suit afterward.
Modern-day baseball encyclopedias notate ERAs for earlier years, but these were computed many years after the actual accomplishments. Negro League
pitchers are often rated by RA, or total runs allowed, since the statistics available for Negro League games did not always distinguish between earned and unearned runs.
, the definition of a "good" ERA varies from year to year. During the dead-ball era
of the 1900s and 1910s, an ERA below 2.00 (two earned runs allowed per nine innings) was considered good. In the late 1920s and 1930s, when conditions of the game changed in a way that strongly favored hitters, a good ERA was below 4.00; only the highest caliber pitchers, for example Dazzy Vance
or Lefty Grove
, would consistently post an ERA under 3.00 during these years. In the 1960s, sub-2.00 ERAs returned, as other influences such as ballparks with different dimensions were introduced. Today, an ERA under 4.00 is again considered good, with pitchers such as Greg Maddux
and Pedro Martínez
achieving this mark.
The all-time single-season record for lowest ERA is 0.86, set by Tim Keefe
in 1880. The modern record is 0.96, set by Dutch Leonard
in 1914. The lowest single-season ERA of a pitcher since 1950 is 1.12, achieved by Bob Gibson
in 1968. The career record is 1.82, held by Ed Walsh
, who played from 1904 through 1917. The active player with the lowest career ERA (among those with more than 1,000 innings pitched) is Mariano Rivera
, with an ERA of 2.21 through the 2011 Major League Baseball season
.
Some sources may list players with infinite ERAs. This can happen if a pitcher allows one or more earned runs without retiring a batter (usually in a single appearance). Additionally, an undefined ERA occasionally occurs at the beginning of a baseball season. It is sometimes incorrectly displayed as zero or as the lowest ranking ERA, even though it is more akin to the highest.
ERA, taken by itself, can also be misleading when trying to objectively judge starting pitcher
s, though not to the extent seen with relief pitchers. The advent of the designated hitter
rule in the American League in 1973 made the pitching environment significantly different. Since then, pitchers spending all or most of their careers in the AL have been at a disadvantage in maintaining low ERAs, compared to National League pitchers who can often get an easy out when pitching to the opposition's pitcher, who is usually not a very good batter. Since 1997, when teams began playing teams from the other league during the regular season, the DH rule is in effect only when such interleague games are played in an American League park.
s tend to be used in the pitcher's batting spot.
As an extreme example, pitchers for the Colorado Rockies
have historically faced many problems, all damaging to their ERAs. The combination of high altitude (5,280 ft or 1,610 m) and a semi-arid climate in Denver causes fly balls to travel up to 10% farther than at sea level. Denver's altitude and low humidity also reduce the ability of pitchers to throw effective breaking balls, due to both reduced air resistance and difficulty in gripping very dry baseballs. These conditions have been countered to some extent since 2002 by the team's use of humidor
s to store baseballs before games. These difficult circumstances for Rockies pitchers may not adversely affect their won-lost records, since opposing pitchers must deal with the same problems. Indeed, hometown hurlers have some advantage in any given game since they are physically acclimated to the altitude and often develop techniques to mitigate the challenges of this ballpark. Still, conditions there tend to inflate Rockies' ERAs relative to the rest of the league.
uses several defense independent pitching statistics
including a Defense-Independent ERA
in an attempt to measure a pitcher's ability regardless of factors outside his control. Further, because of the dependence of ERA on factors over which a pitcher has little control, forecasting future ERAs on the basis of the past ERAs of a given pitcher is not very reliable and can be improved if analysts rely on other performance indicators such as strike out rates and walk rates. For example, this is the premise of Nate Silver
's forecasts of ERAs using his PECOTA
system. Silver also developed a "quick" earned run average (QuikERA or QERA) to calculate an ERA from peripheral statistics including strikeouts, walks, and groundball percentage. Unlike peripheral ERA
OR PERA, it does not take into account park effects. Another statistic derived from ERA is Adjusted ERA
, also called ERA+, which adjusts a pitcher's ERA to a scale where 100 is average for the league and takes into account the various dimensions and other factors of each ballpark.
), and the American League's adoption of the designated hitter rule, ERAs have been noticeably higher than in the early decades of the sport.
The players listed here played their entire careers after 1920. Note that only one of the top five in this list, Whitey Ford, was exclusively a starting pitcher. Hoyt Wilhelm spent considerable time both as a starter and reliever, while the other three are all closers
.
Baseball statistics
Statistics play an important role in summarizing baseball performance and evaluating players in the sport.Since the flow of a baseball game has natural breaks to it, and normally players act individually rather than performing in clusters, the sport lends itself to easy record-keeping and statistics...
, earned run average (ERA) is the mean of earned run
Earned run
In baseball, an earned run is any run for which the pitcher is held accountable . Any runner who tags his base and reaches home plate is scored against the pitcher as an earned run...
s given up by a pitcher
Pitcher
In baseball, the pitcher is the player who throwsthe baseball from the pitcher's mound toward the catcher to begin each play, with the goal of retiring a batter, who attempts to either make contact with the pitched ball or draw a walk. In the numbering system used to record defensive plays, the...
per nine innings pitched
Innings pitched
In baseball, innings pitched are the number of innings a pitcher has completed, measured by the number of batters and baserunners that are put out while the pitcher on the pitching mound in a game. Three outs made is equal to one inning pitched. One out counts as one-third of an inning, and two...
. It is determined by dividing the number of earned runs allowed by the number of innings pitched and multiplying by nine. Runs resulting from defensive errors
Error (baseball)
In baseball statistics, an error is the act, in the judgment of the official scorer, of a fielder misplaying a ball in a manner that allows a batter or baserunner to reach one or more additional bases, when such an advance would have been prevented given ordinary effort by the fielder.The term ...
(including pitchers' defensive errors) are recorded as unearned runs and are not used to determine ERA.
Origins
Henry Chadwick is credited with first devising the statistic, which caught on as a measure of pitching effectiveness after relief pitchingRelief pitcher
A relief pitcher or reliever is a baseball or softball pitcher who enters the game after the starting pitcher is removed due to injury, ineffectiveness, fatigue, ejection, or for other strategic reasons, such as being substituted by a pinch hitter...
came into vogue in the 1900s. Prior to 1900 – and, in fact, for many years afterward – pitchers were routinely expected to pitch a complete game
Complete game
In baseball, a complete game is the act of a pitcher pitching an entire game without the benefit of a relief pitcher.As demonstrated by the charts below, in the early 20th century, it was common for most good Major League Baseball pitchers to pitch a complete game almost every start. Pitchers were...
, and their win-loss record
Win (baseball)
In professional baseball, there are two types of decisions: a win and a loss . In each game, one pitcher on the winning team is awarded a win and one pitcher on the losing team is given a loss in their respective statistics. These pitchers are collectively known as the pitchers of record. Only...
was considered sufficient in determining their effectiveness.
Some means had to be found to calculate the apportionment of earned-run responsibility where multiple pitchers assume responsibility in a single game since pitchers have sole responsibility to put opposing batters out. A pitcher is assessed an earned run for each earned run scored by a batter (or pinch-runner) who reached base while batting against that pitcher. After pitchers like James Otis Crandall
James Otis Crandall
James Otis Crandall was a right-handed pitcher and second baseman. He was the first player to be consistently used as a relief pitcher. Consequently, he was given the nickname Doc by Damon Runyon who said Crandall was "the physician of the pitching emergency". He played from 1908 to 1918,...
and Charlie Hall made names for themselves as relief specialists, gauging a pitcher's effectiveness became more difficult using the traditional method of tabulating wins and losses. The National League
National League
The National League of Professional Baseball Clubs, known simply as the National League , is the older of two leagues constituting Major League Baseball, and the world's oldest extant professional team sports league. Founded on February 2, 1876, to replace the National Association of Professional...
first kept official earned run average statistics in 1912 (the statistic was called "Heydler's statistic" for a while, after then-NL secretary John Heydler
John Heydler
John Arnold Heydler was an American executive in Major League Baseball.-Biography:Born in La Fargeville, New York, he began working as a printer, eventually being employed at the U.S. Government Printing Office....
), with the American League
American League
The American League of Professional Baseball Clubs, or simply the American League , is one of two leagues that make up Major League Baseball in the United States and Canada. It developed from the Western League, a minor league based in the Great Lakes states, which eventually aspired to major...
following suit afterward.
Modern-day baseball encyclopedias notate ERAs for earlier years, but these were computed many years after the actual accomplishments. Negro League
Negro league baseball
The Negro leagues were United States professional baseball leagues comprising teams predominantly made up of African Americans. The term may be used broadly to include professional black teams outside the leagues and it may be used narrowly for the seven relatively successful leagues beginning in...
pitchers are often rated by RA, or total runs allowed, since the statistics available for Negro League games did not always distinguish between earned and unearned runs.
ERA in different decades and baseball eras
As with batting averageBatting average
Batting average is a statistic in both cricket and baseball that measures the performance of cricket batsmen and baseball hitters. The two statistics are related in that baseball averages are directly descended from the concept of cricket averages.- Cricket :...
, the definition of a "good" ERA varies from year to year. During the dead-ball era
Dead-ball era
The dead-ball era is a baseball term used to describe the period between 1900 and the emergence of Babe Ruth as a power hitter in 1919. In 1919, Ruth hit a then league record 29 home runs, a spectacular feat at that time.This era was characterized by low-scoring games and a lack of home runs...
of the 1900s and 1910s, an ERA below 2.00 (two earned runs allowed per nine innings) was considered good. In the late 1920s and 1930s, when conditions of the game changed in a way that strongly favored hitters, a good ERA was below 4.00; only the highest caliber pitchers, for example Dazzy Vance
Dazzy Vance
Charles Arthur "Dazzy" Vance was a star Major League Baseball starting pitcher during the 1920s.-Biography:...
or Lefty Grove
Lefty Grove
Robert Moses "Lefty" Grove was a professional baseball pitcher. After having success in the minor leagues during the early 1920s, Grove became a star in Major League Baseball with the American League's Philadelphia Athletics and Boston Red Sox, winning 300 games in his 17-year MLB career...
, would consistently post an ERA under 3.00 during these years. In the 1960s, sub-2.00 ERAs returned, as other influences such as ballparks with different dimensions were introduced. Today, an ERA under 4.00 is again considered good, with pitchers such as Greg Maddux
Greg Maddux
Gregory Alan Maddux , nicknamed "Mad Dog" and "The Professor", is a former Major League Baseball pitcher. He was the first pitcher in major league history to win the Cy Young Award for four consecutive years , a feat matched only by Randy Johnson...
and Pedro Martínez
Pedro Martínez
Pedro Jaime Martínez is a retired Major League Baseball pitcher. He is an eight-time All-Star, three-time Cy Young Award winner, and 2004 World Series champion...
achieving this mark.
The all-time single-season record for lowest ERA is 0.86, set by Tim Keefe
Tim Keefe
Timothy John "Tim" Keefe , nicknamed "Smiling Tim" and "Sir Timothy", was an American Major League Baseball pitcher. He was one of the most dominating pitchers of the 19th century and posted impressive statistics in one category or another for almost every season he pitched...
in 1880. The modern record is 0.96, set by Dutch Leonard
Dutch Leonard (left-handed pitcher)
Hubert Benjamin "Dutch" Leonard, was an American left-handed pitcher in Major League Baseball who had an 11-year career from 1913–1921, 1924-1925. He played for the Boston Red Sox and Detroit Tigers, and holds the major league modern-era record for the lowest single-season ERA of all time — 0.96...
in 1914. The lowest single-season ERA of a pitcher since 1950 is 1.12, achieved by Bob Gibson
Bob Gibson
Robert "Bob" Gibson is a retired American professional baseball player. Nicknamed "Hoot" and "Gibby", he was a right-handed pitcher who played his entire 17-year Major League Baseball career with St. Louis Cardinals...
in 1968. The career record is 1.82, held by Ed Walsh
Ed Walsh
Edward Augustine Walsh was a Major League Baseball pitcher. He holds the record for lowest career ERA, 1.82.-Baseball career:Born in Plains Township, Pennsylvania, Walsh had a brief though remarkable major league career...
, who played from 1904 through 1917. The active player with the lowest career ERA (among those with more than 1,000 innings pitched) is Mariano Rivera
Mariano Rivera
Mariano Rivera is a Panamanian right-handed baseball pitcher who has played 17 years in Major League Baseball for the New York Yankees. Nicknamed "Mo", Rivera has served as a relief pitcher for most of his career, and since 1997, he has been the Yankees' closer...
, with an ERA of 2.21 through the 2011 Major League Baseball season
2011 Major League Baseball season
The 2011 Major League Baseball season began on Thursday, March 31, and ended on Wednesday, September 28. This marked the first time a season began on a Thursday since , and the first time a regular season ended on a Wednesday since...
.
Some sources may list players with infinite ERAs. This can happen if a pitcher allows one or more earned runs without retiring a batter (usually in a single appearance). Additionally, an undefined ERA occasionally occurs at the beginning of a baseball season. It is sometimes incorrectly displayed as zero or as the lowest ranking ERA, even though it is more akin to the highest.
Starters and relievers
It can be very misleading to judge relief pitchers solely on ERA, because they are charged only for runs scored by batters who reached base while batting against them. Thus, if a relief pitcher enters the game with his team leading by 1 run, with 2 outs and the bases loaded, and then gives up a single which scores 2 runs, he is not charged with those runs. If he retires the next batter (and pitches no more innings), his ERA for that game will be 0.00 despite having surrendered the lead. (He is likely recorded with a blown save in this situation.) Starting pitchers operate under the same rules but are not called upon to start pitching with runners already on base. In addition, relief pitchers know beforehand that they will only be pitching for a relatively short while, allowing them to throw each pitch with maximum energy, unlike starters who typically need to keep something in reserve in case they are asked to pitch 7 or more innings. This freedom to use their maximum energy for a few innings, or even for just a few batters, helps relievers keep their ERAs down.ERA, taken by itself, can also be misleading when trying to objectively judge starting pitcher
Starting pitcher
In baseball or softball, a starting pitcher is the pitcher who delivers the first pitch to the first batter of a game. A pitcher who enters the game after the first pitch of the game is a relief pitcher....
s, though not to the extent seen with relief pitchers. The advent of the designated hitter
Designated hitter
In baseball, the designated hitter rule is the common name for Major League Baseball Rule 6.10, an official position adopted by the American League in 1973 that allows teams to designate a player, known as the designated hitter , to bat in place of the pitcher each time he would otherwise come to...
rule in the American League in 1973 made the pitching environment significantly different. Since then, pitchers spending all or most of their careers in the AL have been at a disadvantage in maintaining low ERAs, compared to National League pitchers who can often get an easy out when pitching to the opposition's pitcher, who is usually not a very good batter. Since 1997, when teams began playing teams from the other league during the regular season, the DH rule is in effect only when such interleague games are played in an American League park.
DH rule
This difference between the leagues (the DH) also affects relievers, but not to the same degree, as National League relievers actually pitch to pitchers far less than do AL starters for a number of reasons, chiefly because relievers are usually active in later innings when pinch hitterPinch hitter
In baseball, a pinch hitter is a substitute batter. Batters can be substituted at any time while the ball is dead ; the manager may use any player that has not yet entered the game as a substitute...
s tend to be used in the pitcher's batting spot.
Location
ERA is also affected somewhat by the ballpark in which a pitcher's team plays half its games, as well as the tendency of hometown official scorers to assign errors instead of base hits in plays that could be either.As an extreme example, pitchers for the Colorado Rockies
Colorado Rockies
The Colorado Rockies are a Major League Baseball team based in Denver, Colorado. Established in 1991, they started play in 1993 and are in the West Division of the National League. The team is named after the Rocky Mountains...
have historically faced many problems, all damaging to their ERAs. The combination of high altitude (5,280 ft or 1,610 m) and a semi-arid climate in Denver causes fly balls to travel up to 10% farther than at sea level. Denver's altitude and low humidity also reduce the ability of pitchers to throw effective breaking balls, due to both reduced air resistance and difficulty in gripping very dry baseballs. These conditions have been countered to some extent since 2002 by the team's use of humidor
Humidor
A humidor is any kind of box or room with constant humidity, and ideal temperature, used to store cigars, cigarettes, or pipe tobacco. For private use, small wooden or acrylic glass humidor boxes for a few dozen cigars are used, while cigar shops may have walk-in humidors, sometimes consisting of a...
s to store baseballs before games. These difficult circumstances for Rockies pitchers may not adversely affect their won-lost records, since opposing pitchers must deal with the same problems. Indeed, hometown hurlers have some advantage in any given game since they are physically acclimated to the altitude and often develop techniques to mitigate the challenges of this ballpark. Still, conditions there tend to inflate Rockies' ERAs relative to the rest of the league.
Sabermetric treatment of ERA
In modern baseball, sabermetricsSabermetrics
Sabermetrics is the specialized analysis of baseball through objective, empirical evidence, specifically baseball statistics that measure in-game activity. The term is derived from the acronym SABR, which stands for the Society for American Baseball Research...
uses several defense independent pitching statistics
Defense independent pitching statistics
In baseball, defense-independent pitching statistics measure a pitcher's effectiveness based only on plays that do not involve fielders: home runs allowed, strikeouts, hit batters, walks, and, more recently, fly ball percentage, ground ball percentage, and line drive percentage...
including a Defense-Independent ERA
Defense-Independent ERA
In baseball statistics,Defense-Independent ERA , created by Voros McCracken, projects what a pitcher's earned run average would have been, if not for the effects of defense and luck on the actual games in which he pitched.-Method:...
in an attempt to measure a pitcher's ability regardless of factors outside his control. Further, because of the dependence of ERA on factors over which a pitcher has little control, forecasting future ERAs on the basis of the past ERAs of a given pitcher is not very reliable and can be improved if analysts rely on other performance indicators such as strike out rates and walk rates. For example, this is the premise of Nate Silver
Nate Silver
Nathaniel Read "Nate" Silver is an American statistician, psephologist, and writer. Silver first gained public recognition for developing PECOTA, a system for forecasting the performance and career development of Major League Baseball players, which he sold to and then managed for Baseball...
's forecasts of ERAs using his PECOTA
PECOTA
PECOTA, an acronym for Player Empirical Comparison and Optimization Test Algorithm, is a sabermetric system for forecasting Major League Baseball player performance. The word is a backronym based on the name of journeyman major league player Bill Pecota, who with a lifetime batting average of .249...
system. Silver also developed a "quick" earned run average (QuikERA or QERA) to calculate an ERA from peripheral statistics including strikeouts, walks, and groundball percentage. Unlike peripheral ERA
Peripheral ERA
Peripheral ERA is a pitching statistic created by the Baseball Prospectus team. It is the expected earned run average taking into account park-adjusted hits, walks, strikeouts, and home runs allowed. Unlike Voros McCracken's DIPS, hits allowed are included...
OR PERA, it does not take into account park effects. Another statistic derived from ERA is Adjusted ERA
Adjusted ERA+
Adjusted ERA+, often simply abbreviated to ERA+ or ERA plus, is a pitching statistic in baseball. It adjusts a pitcher's earned run average according to the pitcher's ballpark and the ERA of the pitcher's league...
, also called ERA+, which adjusts a pitcher's ERA to a scale where 100 is average for the league and takes into account the various dimensions and other factors of each ballpark.
All-time career leaders
| Rank | ERA | Player | Team(s) | Year(s) |
|---|---|---|---|---|
| 1 | 1.82 | Ed Walsh Ed Walsh Edward Augustine Walsh was a Major League Baseball pitcher. He holds the record for lowest career ERA, 1.82.-Baseball career:Born in Plains Township, Pennsylvania, Walsh had a brief though remarkable major league career... |
Chicago (AL) Chicago White Sox The Chicago White Sox are a Major League Baseball team located in Chicago, Illinois.The White Sox play in the American League's Central Division. Since , the White Sox have played in U.S. Cellular Field, which was originally called New Comiskey Park and nicknamed The Cell by local fans... , Boston (NL) Atlanta Braves The Atlanta Braves are a professional baseball club based in Atlanta, Georgia. The Braves are a member of the Eastern Division of Major League Baseball's National League. The Braves have played in Turner Field since 1997.... |
1904–17 |
| 2 | 1.89 | Addie Joss Addie Joss Adrian Joss was a Major League Baseball pitcher. He pitched his entire nine-year baseball career for the Cleveland Bronchos/Naps .-Early life:... |
Cleveland (AL) Cleveland Indians The Cleveland Indians are a professional baseball team based in Cleveland, Ohio. They are in the Central Division of Major League Baseball's American League. Since , they have played in Progressive Field. The team's spring training facility is in Goodyear, Arizona... |
1902–10 |
| 3 | 1.89 | Jim Devlin Jim Devlin James Alexander Devlin was an American Major League Baseball player who played mainly as a first baseman early in his career, then as a pitcher in the latter part... |
Chicago (NA) Chicago Cubs The Chicago Cubs are a professional baseball team located in Chicago, Illinois. They are members of the Central Division of Major League Baseball's National League. They are one of two Major League clubs based in Chicago . The Cubs are also one of the two remaining charter members of the National... , Louisville (NL) Louisville Grays The Louisville Grays were a 19th century U.S. baseball team and charter member of the National League, based in Louisville, Kentucky. They played two seasons, 1876 and 1877, and compiled a record of 65–61. Their home games were at the Louisville Baseball Park. The Grays were owned by... |
1875–77 |
| 4 | 2.02 | Jack Pfiester Jack Pfiester John Albert Pfiester , is a former professional baseball player who pitched in the Major Leagues from 1903-1911.... |
Pittsburgh (NL) Pittsburgh Pirates The Pittsburgh Pirates are a Major League Baseball club based in Pittsburgh, Pennsylvania. They play in the Central Division of the National League, and are five-time World Series Champions... , Chicago (NL) Chicago Cubs The Chicago Cubs are a professional baseball team located in Chicago, Illinois. They are members of the Central Division of Major League Baseball's National League. They are one of two Major League clubs based in Chicago . The Cubs are also one of the two remaining charter members of the National... |
1903–04, 1906–11 |
| 5 | 2.03 | Smoky Joe Wood | Boston (AL) Boston Red Sox The Boston Red Sox are a professional baseball team based in Boston, Massachusetts, and a member of Major League Baseball’s American League Eastern Division. Founded in as one of the American League's eight charter franchises, the Red Sox's home ballpark has been Fenway Park since . The "Red Sox"... , Cleveland (AL) Cleveland Indians The Cleveland Indians are a professional baseball team based in Cleveland, Ohio. They are in the Central Division of Major League Baseball's American League. Since , they have played in Progressive Field. The team's spring training facility is in Goodyear, Arizona... |
1908–15, 1917–22 |
Career leaders in the live-ball era (post-1920)
Because of rules changes post-1920, most notably the abolition of the spitball and frequent replacement of soiled or scuffed baseballs, the increased importance of the home run (largely due to Babe RuthBabe Ruth
George Herman Ruth, Jr. , best known as "Babe" Ruth and nicknamed "the Bambino" and "the Sultan of Swat", was an American Major League baseball player from 1914–1935...
), and the American League's adoption of the designated hitter rule, ERAs have been noticeably higher than in the early decades of the sport.
The players listed here played their entire careers after 1920. Note that only one of the top five in this list, Whitey Ford, was exclusively a starting pitcher. Hoyt Wilhelm spent considerable time both as a starter and reliever, while the other three are all closers
Closer (baseball)
In baseball, a closing pitcher, more frequently referred to as a closer , is a relief pitcher who specializes in closing out games, i.e., getting the final outs in a close game. Closers often appear when the score is close, and the role is often assigned to a team's best reliever. A small number of...
.
| Rank | ERA | Player | Team(s) | Year(s) |
|---|---|---|---|---|
| 1 | 2.21 | Mariano Rivera Mariano Rivera Mariano Rivera is a Panamanian right-handed baseball pitcher who has played 17 years in Major League Baseball for the New York Yankees. Nicknamed "Mo", Rivera has served as a relief pitcher for most of his career, and since 1997, he has been the Yankees' closer... |
New York (AL) New York Yankees The New York Yankees are a professional baseball team based in the The Bronx, New York. They compete in Major League Baseball in the American League's East Division... |
1995– |
| 2 | 2.31 | Billy Wagner Billy Wagner William Edward Wagner , nicknamed "Billy the Kid", is a retired Major League Baseball relief pitcher. He pitched for the Houston Astros , the Philadelphia Phillies , the New York Mets , the Boston Red Sox , and the Atlanta Braves... |
Atlanta Atlanta Braves The Atlanta Braves are a professional baseball club based in Atlanta, Georgia. The Braves are a member of the Eastern Division of Major League Baseball's National League. The Braves have played in Turner Field since 1997.... , Houston Astros Houston Astros The Houston Astros are a Major League Baseball team located in Houston, Texas. They are a member of the National League Central division. The Astros are expected to join the American League West division in 2013. Since , they have played their home games at Minute Maid Park, known as Enron Field... , Philadelphia Phillies Philadelphia Phillies The Philadelphia Phillies are a Major League Baseball team. They are the oldest continuous, one-name, one-city franchise in all of professional American sports, dating to 1883. The Phillies are a member of the Eastern Division of Major League Baseball's National League... , New York Mets New York Mets The New York Mets are a professional baseball team based in the borough of Queens in New York City, New York. They belong to Major League Baseball's National League East Division. One of baseball's first expansion teams, the Mets were founded in 1962 to replace New York's departed National League... , Boston Red Sox Boston Red Sox The Boston Red Sox are a professional baseball team based in Boston, Massachusetts, and a member of Major League Baseball’s American League Eastern Division. Founded in as one of the American League's eight charter franchises, the Red Sox's home ballpark has been Fenway Park since . The "Red Sox"... |
1995–2010 |
| 3 | 2.52 | Hoyt Wilhelm Hoyt Wilhelm James Hoyt Wilhelm was an American Major League Baseball pitcher. He was elected to the Baseball Hall of Fame in 1985.... |
New York (NL) San Francisco Giants The San Francisco Giants are a Major League Baseball team based in San Francisco, California, playing in the National League West Division.... , St. Louis St. Louis Cardinals The St. Louis Cardinals are a professional baseball team based in St. Louis, Missouri. They are members of the Central Division in the National League of Major League Baseball. The Cardinals have won eleven World Series championships, the most of any National League team, and second overall only to... , Cleveland Cleveland Indians The Cleveland Indians are a professional baseball team based in Cleveland, Ohio. They are in the Central Division of Major League Baseball's American League. Since , they have played in Progressive Field. The team's spring training facility is in Goodyear, Arizona... , Baltimore Baltimore Orioles The Baltimore Orioles are a professional baseball team based in Baltimore, Maryland in the United States. They are a member of the Eastern Division of Major League Baseball's American League. One of the American League's eight charter franchises in 1901, it spent its first year as a major league... , Chicago (AL) Chicago White Sox The Chicago White Sox are a Major League Baseball team located in Chicago, Illinois.The White Sox play in the American League's Central Division. Since , the White Sox have played in U.S. Cellular Field, which was originally called New Comiskey Park and nicknamed The Cell by local fans... , Los Angeles (Anaheim) Los Angeles Angels of Anaheim The Los Angeles Angels of Anaheim are a professional baseball team based in Anaheim, California, United States. The Angels are a member of the Western Division of Major League Baseball's American League. The "Angels" name originates from the city in which the team started, Los Angeles... , Atlanta Atlanta Braves The Atlanta Braves are a professional baseball club based in Atlanta, Georgia. The Braves are a member of the Eastern Division of Major League Baseball's National League. The Braves have played in Turner Field since 1997.... , Chicago (NL) Chicago Cubs The Chicago Cubs are a professional baseball team located in Chicago, Illinois. They are members of the Central Division of Major League Baseball's National League. They are one of two Major League clubs based in Chicago . The Cubs are also one of the two remaining charter members of the National... , Los Angeles (NL) Los Angeles Dodgers The Los Angeles Dodgers are a professional baseball team based in Los Angeles, California. The Dodgers are members of Major League Baseball's National League West Division. Established in 1883, the team originated in Brooklyn, New York, where it was known by a number of nicknames before becoming... |
1952–72 |
| 4 | 2.75 | Whitey Ford Whitey Ford Edward Charles "Whitey" Ford is a former Major League Baseball pitcher who spent his entire 18-year career with the New York Yankees. He was voted into the Baseball Hall of Fame in 1974.-Early life and career:... |
New York Yankees (AL) New York Yankees The New York Yankees are a professional baseball team based in the The Bronx, New York. They compete in Major League Baseball in the American League's East Division... |
1950–67 |
| 5 | 2.76 | Dan Quisenberry Dan Quisenberry Dan Raymond "Quiz" Quisenberry was an American right-handed relief pitcher in Major League Baseball who played primarily for the Kansas City Royals... |
Kansas City Kansas City Royals The Kansas City Royals are a Major League Baseball team based in Kansas City, Missouri. The Royals are a member of the Central Division of Major League Baseball's American League. From 1973 to the present, the Royals have played in Kauffman Stadium... , St. Louis St. Louis Cardinals The St. Louis Cardinals are a professional baseball team based in St. Louis, Missouri. They are members of the Central Division in the National League of Major League Baseball. The Cardinals have won eleven World Series championships, the most of any National League team, and second overall only to... , San Francisco San Francisco Giants The San Francisco Giants are a Major League Baseball team based in San Francisco, California, playing in the National League West Division.... |
1979–90 |
See also
- Adjusted ERA+Adjusted ERA+Adjusted ERA+, often simply abbreviated to ERA+ or ERA plus, is a pitching statistic in baseball. It adjusts a pitcher's earned run average according to the pitcher's ballpark and the ERA of the pitcher's league...
(Park-adjusted ERA) - Catcher's ERACatcher's ERACatcher's ERA or CERA in baseball statistics is the earned run average of the pitchers pitching when the catcher in question is catching. Its primary purpose is to measure a catcher's game-calling, rather than his effect on the opposing team's running game. Craig Wright first described the...
- Component ERAComponent ERAComponent ERA or ERC is a baseball statistic invented by Bill James. It attempts to forecast a pitcher's earned run average from the number of hits and walks allowed rather than the standard formula of average number of earned runs per nine innings...
- Defense-Independent ERADefense-Independent ERAIn baseball statistics,Defense-Independent ERA , created by Voros McCracken, projects what a pitcher's earned run average would have been, if not for the effects of defense and luck on the actual games in which he pitched.-Method:...
- FIP
- Earned runEarned runIn baseball, an earned run is any run for which the pitcher is held accountable . Any runner who tags his base and reaches home plate is scored against the pitcher as an earned run...
- PERAPeripheral ERAPeripheral ERA is a pitching statistic created by the Baseball Prospectus team. It is the expected earned run average taking into account park-adjusted hits, walks, strikeouts, and home runs allowed. Unlike Voros McCracken's DIPS, hits allowed are included...
- QERA
- Run averageRun averageIn baseball statistics, run average refers to measures of the rate at which runs are allowed or scored. For pitchers, the run average is the number of runs—earned or unearned—allowed per nine innings...