What does era mean in MLB?
In Major League Baseball, ERA (earned run average) has to do with pitching. The earned run average (ERA) is a measure of a pitcher’s effectiveness, calculated as the average number of earned runs allowed by a pitcher for every nine innings pitched. The calculation is made by taking the number of earned runs allowed times 9 divided by the innings pitched. An earned run is any run that the opponent scores against a pitcher except for runs scored as a result of errors. For more on the definition of an earned run please see: http://www.baseball-almanac.com/rule10.s… The ERA can be calculated using the following formula: (earned runs / innings pitched) x 9. Thus, if a pitcher is charged with 19 earned runs in his first 89 innings pitched, the pitcher’s ERA would be 19 divided by 89, which is .2135, times 9, which is 1.92. (19 runs / 89 innings) x 9 = 1.92.
