This article was published in the Spring 2011 Baseball Research Journal
The strike-shortened 1981 season resulted in confusion as to who had the lowest earned run average in the American League. To qualify, a pitcher has to have pitched one inning for each of his team’s games played. In most years this would mean 162 innings, but the strike had reduced each team’s games to just over 100. The apparent winner was Sammy Stewart of the Baltimore Orioles, with an ERA of 2.32356 in 112 1⁄3 innings pitched. Finishing just behind Stewart was Steve McCatty of the Oakland A’s, whose ERA was 2.32670 in 185 2⁄3 innings pitched.
Due, however, to a no-longer-extant rule regarding the rounding of innings pitched, McCatty was declared the official leader. Stewart’s 112 1⁄3 inning total was rounded down to 112, while McCatty’s 185 2⁄3 innings were rounded up to 186. McCatty got credit for an extra third of an inning without allowing a run, and Stewart lost a third of a scoreless inning. That made McCatty’s ERA 2.32 and Stewart’s 2.33. While the findings were appealed, the Rules Committee of the day upheld the result because it conformed to the established practice. The rule was changed the next year and fractions of innings were no longer rounded up or down.
Results were not applied retroactively (nor should they be), however, so nearly all sources continue to list McCatty as the AL’s ERA leader in 1981. There is one exception, though. Baseball-Reference.com has Dave Righetti of the Yankees as the 1981 leader. Righetti’s ERA was 2.05, significantly lower than McCatty’s or Stewart’s. But Righetti pitched just 105 1⁄3 innings, and his team played 107 games.
It takes at least a slight bending of the rules to recognize Righetti as the official leader, an interpretation that would never be contemplated in a normal season. But 1981 was different, which leaves us with legitimate arguments for three different pitchers as the American League’s ERA leader that year.