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The lowest career ERA is 1.82, set by Chicago White Sox pitcher Ed Walsh.

In baseball statistics, earned run average (ERA) is the mean of earned runs 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.

Origins[link]

Henry Chadwick is credited with first devising the statistic, which caught on as a measure of pitching effectiveness after relief pitching 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 determine and calculate the apportionment of earned-run responsibility where multiple pitchers have performed in a single game. Since pitchers have sole responsibility to put opposing batters out, they must assume responsibility when a batter they do not retire at the plate moves to base, and eventually reaches home, scoring a run. 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.

ERA in different decades and baseball eras[link]

As with batting average, 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.

The all-time single-season record for the lowest ERA, according to www.mlb.com, the official website of Major League Baseball, is held by Dutch Leonard, who in 1914 had an earned run average of 0.96, pitching 224.2 innings with a win-loss record of 19-5. The all-time record for the lowest single season earned run average by a pitcher pitching 300 or more innings is 1.12, set by Bob Gibson in 1968. The record for the lowest career earned run average 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 researchers dissent from the official Major League Baseball record and claim that the pitcher with the all-time lowest earned run average is Tim Keefe, who had an earned run average of 0.86 in 1880 while appearing in 12 of his team's 83 games and pitched 105 innings (with a win-loss record of 6-6). But a purported record based on so few innings pitched is highly misleading. Over the years, more than a dozen part-time pitchers have pitched 105 or more innings and had an earned run average lower than 0.86. Orel Hershiser pitched 60 innings in 1988 with an earned run average of 0.00. Major League Baseball recognizes many records from the 19th Century--including Will White's 1879 record of 680 innings pitched, Charles Radbourne's 1884 record of 59 wins, and Pud Galvin's 1883 record for 75 games started, but does not recognize Keefe as the pitcher having the all-time lowest single season earned run average.

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.

Other external factors[link]

Starters and relievers[link]

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 pitchers, 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.

DH rule[link]

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 hitters tend to be used in the pitcher's batting spot.

Location[link]

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 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 humidors 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[link]

In modern baseball, sabermetrics 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.^[1] 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.^[2] 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.

All-time career leaders[link]

Career leaders in the live-ball era (post-1920)[link]

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 Ruth), and the American League's adoption of the designated hitter rule, ERAs have been noticeably higher than in the early decades of the sport.

This is a list of the lowest ERAs among pitchers that played their entire careers after 1920. Note that only one of the top five (Whitey Ford) was primarily a starting pitcher. Hoyt Wilhelm was a reliever for most of his career, while the other three are all closers.

See also[link]

Baseball portal

• Adjusted ERA+ (Park-adjusted ERA)
• Catcher's ERA
• Component ERA
• Defense-Independent ERA
• FIP
• Earned run
• PERA
• QERA
• Run average

References[link]

In baseball statistics, run average (RA) 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. It is calculated using this formula:

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathrm{RA} = 9 \cdot \frac{\mathrm{R}}{\mathrm{IP}}

where

• R = Runs
• IP = Innings pitched

Run average for pitchers differs from the more commonly used earned run average (ERA) by adding unearned runs to the numerator. This measure is also known as total run average (TRA) or runs allowed average. For batters, the run average is the number of runs scored per at bat.^[1]

Run average for pitchers[link]

Although presentations of pitching statistics generally feature the ERA rather than the RA, the latter statistic is notable for both historical and analytical reasons. For early leagues or leagues for which statistics must be calculated from box scores, such as the Negro leagues, data on earned runs may be unavailable and RA may be the only statistic available.^[2] The analytical case for RA appeared as early as 1976, when sportswriter Leonard Koppett proposed that RA would be a better measure of pitcher performance than ERA.^[3] Subsequently, sabermetrician Bill James wrote, "I think that the distinction between earned runs and unearned runs is silly and artificial, a distinction having no meaning except in the eyes of some guy up in the press box."^[4]

In baseball, defense—that is, preventing the opponent from scoring runs—is the joint responsibility of the pitcher and the fielders. ERA attempts to adjust for some of the influence of the fielders on a pitcher's runs allowed by removing runs that are scored because of fielding errors—that is, unearned runs. However, removing unearned runs doesn't adequately adjust for the effects of defensive support, because it makes no adjustment for other important aspects of fielding, such as proficiency at turning double plays, throwing out base stealers, and fielding range. Errors are the only aspect of fielding that ERA adjusts for, and are generally regarded as a small part of fielding in modern baseball.^[5]

Another problem with ERA is the inconsistency with which official scorers call plays as errors. The rules give scorers considerable discretion regarding the plays that can be called as errors. Researcher Craig R. Wright found large differences between teams in the rate at which their scorers called errors, and even found some evidence of home team bias—that is, calling errors to favor the statistics of players for the home team.^[6]

While ERA doesn't charge the pitcher for the runs that result from errors, it may tend to over correct for the influence of fielding. Even though unearned runs would not have scored without an error, in most cases the pitcher also contributes to the scoring of the unearned run—either by allowing the opposing player to reach base via a walk or hit, or by allowing a subsequent batter a hit that advances and scores the runner. During the early days of baseball history, this over correction for fielding errors caused pitchers on bad teams to be overrated in terms of ERA.^[7]

Removing unearned runs in calculating ERA may be useful if they are unrelated to pitcher performance, but Wright concludes that fielding errors are somewhat dependent on a pitcher's style. Because errors occur most often on ground balls, pitchers with high strikeout rates who give up fly balls are likely to give up fewer unearned runs than groundball control-type pitchers. For example, Ron Guidry—a flyball power pitcher—and Tommy John—a groundball control pitcher—were teammates on the Yankees from 1979 to 1982, supported by the same defense. During that period, 13.7% of John's runs allowed were unearned, compared to 9.8% of Guidry's. Wright concludes that this difference is attributable to their pitching styles, and thus, that unearned runs are partially attributable to the pitcher.^[8]

Adjusted RA+[link]

Similar to adjusted ERA+, it is possible to adjust RA for the ballpark effects and compare it to the league average. The formula for this adjustment is:

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathrm{RA+} = 100 \cdot \frac{\mathrm{lgRA}}{\mathrm{RA}}

where

• lgRA = park-adjusted league run average
• RA = the pitcher's run average.

Values of RA+ above 100 indicate better-than-average pitching performance. Unlike unadjusted RA, which must be higher than unadjusted ERA, a pitcher's adjusted RA+ can be either higher or lower than his adjusted ERA+.

See also[link]

• Defense independent pitching statistics

Notes[link]

References[link]

• Holway, John B. (2001). The Complete Book of Baseball's Negro Leagues: The Other Half of Baseball History. Fern Park, FL: Hastings House Publishers. ISBN 0-8038-2007-0. 
• James, Bill (1986). The Bill James Historical Baseball Abstract. New York: Villard Books. ISBN 0-394-53713-0. 
• James, Bill (1987). The Bill James Baseball Abstract 1987. New York: Ballantine Books. ISBN 0-345-34180-5. 
• Thorn, John; Pete Palmer (1982). The Hidden Game of Baseball. Garden City, NY: Doubleday. ISBN 0-385-18283-X. 
• Wright, Craig R.; Tom House (1989). The Diamond Appraised. New York: Simon & Schuster. ISBN 0-671-67769-1. 

In baseball, an earned run is any run for which the pitcher is held accountable (i.e., the run scored as a result of normal pitching, and not due to a fielding error or a passed ball). Any runner(s) who tags his base and reaches home plate is scored against the pitcher as an earned run(s). An error made by the pitcher in fielding at his position is counted the same as an error by any other player.

Earned runs are specially denoted because of their use in calculating a pitcher's earned run average – the number of earned runs allowed per 9 innings (regulation game) pitched. Earned runs proceed from the theory that the pitcher has sole responsibility to earn strikes against opposing batter(s) until at least three batters are retired in each inning of play, and nine innings (a complete game) are pitched.

To determine whether a run is earned, the official scorer must reconstruct the inning as it would have occurred without the errors (for purposes of this rule, the "errors" also include passed balls). The benefit of the doubt is always given to the pitcher in determining which bases would have been reached by errorless play.

If no errors and no passed balls occur during the inning, all runs scored are automatically earned (assigned responsible to the pitcher). In a few cases, an error can be rendered harmless while the inning is still going on. For example, a runner on first base advances to second on a passed ball. The next batter walks. Since the runner would now have been at second anyway, the passed ball no longer has any impact on the earned/unearned calculation.

Unearned run[link]

A run is counted as unearned when:

• A batter reaches base on an error (including catcher's interference), and later scores a run in that inning by any means.
• A baserunner remains on base as the result of an error on a fielder's choice play that would put the baserunner out except for the error, and subsequently scores.
• A batter reaches first base on a passed ball (but not a wild pitch) and subsequently scores by any means.
• A baserunner scores after the third out would have been made except for an error other than catcher's interference.
• A batter reaches base on a fielder's choice which removes a baserunner who has reached base safely on an error or has remained on base as the result of an error, reaching first base on a passed ball on a called or swinging third strike, or remained on base on an error on a fielders' choice play that should have retired him, and subsequently scores.
• A batter or runner advances one or more bases on an error or passed ball and scores on a play that would otherwise not have provided the opportunity to score.

In the first two cases above, "on an error" includes situations where the batter makes a clean hit (or walks, is hit by pitch, reaches base on a fielder's choice in which no out is made, or reaches base on a wild pitch on a called or swinging third strike), but should have been out earlier in his at bat on a foul fly ball which was dropped by a fielder for an error. This also includes any run (or any subsequent run) that scores on plays that result in outs with one out or a double play with none out if an error has extended the inning.

While the inning is still being played, this last scenario can cause a temporary situation where a run has already scored, but its earned/unearned status is not yet certain. For example, with two outs, a runner on third base scores on a passed ball. For the time being, the run is unearned since the runner should still be at third. If the batter strikes out to end the inning, it will stay that way. If the batter gets a base hit, which would have scored the runner anyway, the run now becomes earned.

A runner who reaches on catcher's interference and subsequently scores with two outs scores an unearned run, but baserunners who subsequently score after the runner who has reached on catcher's interference exclusively on clean plays score earned runs; the baserunner cannot be assumed to have been put out except for the error. (Rule 10.16(4)).

Neither the use of a pinch-runner to replace a baserunner who represents an unearned run nor the use of a pinch-hitter to continue the turn at bat of a batter who would be out except for an error transforms a run scored by such a person or his successors on base from an unearned run to an earned run.

When pitchers are changed in the middle of an inning, and one or more errors have already occurred, it is possible to have a run charged as earned against a specific pitcher, but unearned to the team. The simplest example is when the defensive team records two outs and makes an error on a play that would have been the third out. A new pitcher comes into the game, and the next batter hits a home run. The runner who reached on the error comes around to score, and his run is unearned to both the prior pitcher and the team. However, the run scored by the batter is counted as earned against the relief pitcher, but unearned to the team (since there should have already been three outs). Had the team not switched pitchers, neither run would be counted as an earned run because that pitcher should have already been out of that inning.

A pitcher is only charged with the number of runners that reached base while he was pitching, and this does not include baserunners who reach base as the result of a fielder's choice play that removes an existing runner; such a runner is charged to the pitcher whose baserunner has been removed by the fielder's choice play. When a pitching change occurs, the new pitcher is said to "inherit" any runners that are on base at the time, and if they later score, those runs are charged (earned or unearned) to the prior pitcher. Most box scores now list inherited runners, and the number that scored, as a statistic for the relief pitcher.

Historical differences[link]

In the early history of major league baseball, the difference between the number of earned runs given up by a pitcher and the total number of runs given up was much more significant than today. For instance, Jim Devlin in 1876 pitched 66 complete games (662 innings pitched) with a 1.56 ERA but managed to record only five shutouts. The seeming discrepancy comes from the difference in the number of allowed runs (309) versus earned runs (108).

External links[link]

• Major League Baseball Rule 10.16 - Determining Earned Runs

See also[link]

• Baseball statistics
• Earned run average
• Run average

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (July 2008)

Dr. Wei Yen is a software developer and entrepreneur. He has been involved with several companies, including most recently as chairman and founder of AiLive. Dr. Yen and his brother David Yen published the paper "Data Coherence Problem in a Multicache System" along with King-sun Fu which describes a practical cache coherence protocol.

Career[link]

Wei Yen served as the Director of Software Engineering for Cydrome Inc, where he worked with his brother David, who served as the Director of Hardware Engineering. They were the major contributors to the Cydra-5 mini-supercomputer. The system was a combination of a VLIW ECL-based processor used for scientific applications and a multi-processor system designed for a bus architecture based on their Cache Coherence protocol.

Wei served as Senior Vice President of SGI. In 1996, Dr. Yen left SGI and founded TVsoft, a maker of interactive software for television setup devices. It was renamed Navio, a company that merged with Oracle's Network Computer (NCI). It became liberate and then went public in July, 1999. It went up at a $12 Billion valuation in early 2000 with a revenue run rate of $25 Million.^[1]

In parallel, Wei Yen founded a company called ArtX, employed with former SGI graphics engineers. ArtX received the contract to deliver the Nintendo Gamecube's Flipper graphics chip. It was acquired in February 2000 for $400 Million by ATI. It led to the greatly improved R300 graphics chip family. Wei later joined ATI's board of directors.^[1]

Wei Yen is the chairman and founder of AiLive, the company partnered with Nintendo in developing software tools for programmers working with the Wii Remote controller and Wii MotionPlus attachment.^[1]

He is also the founder of iGware, a company that offers cloud computer services to its customers. Its most important customer is Nintendo - almost all of the companies founded by Wei Yen seem to share Nintendo as their main customer. iGware's cloud services power the online services of the Nintendo DS, the Nintendo 3DS, the Nintendo Wii and soon the Nintendo Wii U. However, in July 2011, Acer, of which Wei Yen is a former board member, acquired the US-based iGware for 320 million US-$ and therefore, iGware will become a part of Acer's company structure and will continue to provide cloud services. In this context, iGware's US-team will collaborate with new teams in Taiwan and China. Furthermore, iGware will change its name to Acer Cloud Technology Co and will continue to be headed by Wei Yen.^[2]

See also[link]

• IQue Player

References[link]

This biographical article relating to a computer specialist is a stub. You can help Wikipedia by expanding it. v t e

This biographical article needs additional citations for verification. Please help by adding reliable sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately, especially if potentially libelous or harmful. (May 2009)

David Pauley
Los Angeles Angels of Anaheim – No. 35
Relief pitcher
Born: (1983-06-17) June 17, 1983 (age 29) Longmont, Colorado
Bats: Right	Throws: Right
MLB debut
May 31, 2006 for the Boston Red Sox
Career statistics (through May 19, 2012)
Win–loss record	9–18
Earned run average	4.55
Strikeouts	120
Teams
Boston Red Sox (2006, 2008) Seattle Mariners (2010–2011) Detroit Tigers (2011) Los Angeles Angels of Anaheim (2012–present)

David Wayne Pauley (born June 17, 1983) is an American professional baseball pitcher who plays for the Los Angeles Angels of Anaheim. He bats and throws right-handed.

Career[link]

Early life[link]

Pauley is a graduate of Longmont High School in Longmont, Colorado.

San Diego Padres[link]

An eighth round pick by San Diego in 2001, Pauley posted a 7–12 record with a 4.17 ERA for the Padres A-class affiliate, the Lake Elsinore Storm, as their seventh best prospect in 2004.

Boston Red Sox[link]

On December 20, 2004, the Padres traded Pauley along with Jay Payton, Ramón Vázquez, and cash to the Boston Red Sox for Dave Roberts.^[1]

As a member of the Portland Sea Dogs rotation in 2005, he went 9–7 with 104 strikeouts and a 3.81 ERA in 156 innings pitched.

Pauley started 2006 in Portland. He posted a 2–3 with a 2.39 ERA in 10 starts for the Sea Dogs before making his major league debut on May 31 starting for Boston in place of the injured David Wells. He pitched 4⅓ innings against the Toronto Blue Jays and did not record a decision. In his 16 innings pitched for the Boston Red Sox, Pauley recorded a 7.88 ERA.

In 2007, Pauley was rated by Baseball America as the number 26 prospect in the Red Sox farm system.^{[citation needed]} Pauley spent the entire 2007 season playing for the Pawtucket Red Sox. The Red Sox invited him to spring training in 2008, but was sent back to the minors on March 8, 2008.^[2] In January 2009, Pauley was designated for assignment in order to make room for the newly-signed John Smoltz.

Baltimore Orioles[link]

On January 19, Pauley was traded to the Baltimore Orioles for pitcher Randor Bierd.

Seattle Mariners[link]

On December 22, 2009, Pauley signed a minor league contract with the Seattle Mariners. On August 13, 2010, he earned his first major league win versus the Cleveland Indians.

Detroit Tigers[link]

On July 30, 2011, Pauley was traded to the Detroit Tigers along with Doug Fister for Charlie Furbush, Casper Wells, Chance Ruffin and minor leaguer Francisco Martinez.^[3] Pauley was released by the Detroit Tigers on March 12, 2012 ^[4] and became a free agent after clearing waivers on March 15.

Los Angeles Angels[link]

The Angels signed David Pauley to a minor league contract on March 23, 2012. He was called up to the majors on May 7, 2012, but was designated for assignment on May 24.

Pitching style[link]

Pauley is a sinkerball pitcher,^[5] and as such his success relies on his ability to keep the ball down in the strike zone, and when contact is made, to get ground-ball outs. Pauley also has the standard fastball, curveball, and changeup in his repertoire.^{[citation needed]} His fastball hits the high 80 MPH range and his curveball has more of a sweeping motion than the standard 12-to-6 movement seen from most minor-league pitchers.^{[citation needed]}

References[link]

External links[link]

Baseball portal

• Career statistics and player information from MLB, or ESPN, or Baseball-Reference, or Fangraphs, or The Baseball Cube, or Baseball-Reference (Minors)