List of Major League Baseball earned run average champions

• abstract: In baseball, earned run average (ERA) is a statistic used to evaluate pitchers, calculated as the mean of earned runs given up by a pitcher per nine innings pitched. A pitcher is assessed an earned run for each run scored by a baserunner who reached base while batting against that pitcher, whether by hit, base on balls or "walk", or being hit by a pitched ball; an earned run can be charged after the pitcher is relieved if he allows the runner before leaving the game.

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