<P> The lowest single - season ERA in league history was posted by Tim Keefe , whose 0.86 ERA in 105 innings pitched for the National League 's Troy Trojans in 1880 led his closest competitor by . 52 runs . In the American League , Dutch Leonard 's 0.96 ERA is a single - season record . Keefe and Leonard are the only two pitchers ever to allow less than one run per nine innings pitched in a single season . The widest margin of victory for an ERA champion is 1.96 runs , achieved when Martínez ' 1.74 ERA led Clemens ' 3.70 in the American League during the 2000 season . The largest margin of victory in the National League is 1.26 runs -- Dazzy Vance 's 2.61 ERA over Carl Hubbell 's 3.87 in 1930 . The smallest margin of victory for an ERA champion is . 009 runs . Although the statistic is traditionally recorded to two decimal places by most sources , the 1988 American League title was decided by a margin of less than one hundredth of a run when Allan Anderson 's ERA of 2.446 ( 55 earned runs in ​ 202 ⁄ innings ) bested Teddy Higuera 's 2.455 mark ( 62 earned runs in ​ 227 ⁄ innings ) . Other contests decided by one hundredth or less include Luis Tiant 's 1.91 ERA ahead of Gaylord Perry 's 1.92 in 1972 and Mark Fidrych ( 2.34 ) over Vida Blue ( 2.35 ) in 1976 . </P>
<P> The lowest single - season ERA in league history was posted by Tim Keefe , whose 0.86 ERA in 105 innings pitched for the National League 's Troy Trojans in 1880 led his closest competitor by . 52 runs . In the American League , Dutch Leonard 's 0.96 ERA is a single - season record . Keefe and Leonard are the only two pitchers ever to allow less than one run per nine innings pitched in a single season . The widest margin of victory for an ERA champion is 1.96 runs , achieved when Martínez ' 1.74 ERA led Clemens ' 3.70 in the American League during the 2000 season . The largest margin of victory in the National League is 1.26 runs -- Dazzy Vance 's 2.61 ERA over Carl Hubbell 's 3.87 in 1930 . The smallest margin of victory for an ERA champion is . 009 runs . Although the statistic is traditionally recorded to two decimal places by most sources , the 1988 American League title was decided by a margin of less than one hundredth of a run when Allan Anderson 's ERA of 2.446 ( 55 earned runs in ​ 202 ⁄ innings ) bested Teddy Higuera 's 2.455 mark ( 62 earned runs in ​ 227 ⁄ innings ) . Other contests decided by one hundredth or less include Luis Tiant 's 1.91 ERA ahead of Gaylord Perry 's 1.92 in 1972 and Mark Fidrych ( 2.34 ) over Vida Blue ( 2.35 ) in 1976 . </P>
who has the lowest era in mlb history
who has the lowest era in mlb history
Tim Keefe
Tim Keefe