In baseball statistics, earned run average (ERA) is the average of earned runs allowed by a pitcher per nine innings pitched (i.e. the traditional length of a game).

Earned run average represents the number of earned runs a pitcher allows per nine innings -- with earned runs being any runs that scored without the aid of an error or a passed ball. ERA is the most commonly accepted statistical tool for evaluating pitchers. The formula for finding ERA is: 9 x earned runs / innings pitched.

In baseball statistics, Earned Run Average, or ERA, is one of the most well-known pitching statistics and represents the average number of earned runs a pitcher will give up per nine-inning game. It is determined by dividing the total number of earned runs allowed by the number of innings pitched and multiplying by nine.

防禦率 （英語： ERA, earned run average），又稱 自責分率，是 棒球術語，指 投手 平均每場球所失的 自責分，分值越低则代表投手表现越好。 投手因為被打 安打 或 四壞 而讓人上壘（因為 野手 失誤 而上壘的不算），然後又因任何原因讓這上壘的人回來 得分 （就算換投手，惟壘上那人還是原投手要負責的），此時的得分則為自責分。 若某野手失誤讓人上壘，而該守備足以結束此局者，之後只要有 失分，都不算自責分；因為若沒發生失誤，此局可以提早結束，所以不是投手 …

Dec 24, 2024 · ERA (Earned Run Average) is the average number of earned runs a pitcher has allowed per every 9 innings he pitches. This is one of the most useful calculations in baseball, as it shows the pitcher's overall effectiveness.

投手防御率又称自责分率，指投手平均每场球所失的自责分。 投手因为被打安打或四坏球而让人上垒（因为野手失误而上垒的不算），然后又 因任 何原因让这上垒的人回来得分（就算换投手 …

Jul 13, 2024 · An earned run average (ERA) of 0.5 signifies a highly effective pitcher. In general, a lower ERA score indicates a better performance on the mound. The all-time lowest career earned run average is 1.82, a record held by Ed Walsh, who played from 1904 to 1917.

May 22, 2023 · Earned Run Average, or ERA, lies at the heart of evaluating a pitcher's effectiveness in a baseball game. Developed by English-American sportswriter and statistician Henry Chadwick, ERA measures the number of earned runs allowed per nine innings pitched.

May 15, 2022 · A pitcher's Earned Run Average (aka ERA) is a primary measure of his success. It is similar, but not identical to, run average. It is expressed as an average number of opponents' earned runs scored per notional nine inning game: ERA = (Earned Runs Allowed * 9) / …

Aug 14, 2024 · Calculate your earned run average using this ERA calculator. Enter the earned runs, innings pitched, and game innings to determine your ERA.