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| (Added 17 November 2016)
One of the important individual pitching statistics is earned run average (or earned runs average or ERA). It is calculated by mulitplying the number of earned runs (ER) a pitcher allows by 9, and then dividing by the number of innings pitched (IP).
The lowest ERA achieved by a pitcher over a season, with at least 100 IP, is 1.54, held by Ricky Terrazas in 2012. The lowest career ERA, with at least 500 IP, is held by Iron Arm with 2.23.