Christopher Winter followed up his study of circadian rhythms by trying to find out whether a person's sleep preference
affected his pitching performance. So he picked out 18 pitchers, adjusted for talent and for any jet lag effect, and studied more than 700 daytime innings and 800 nighttime innings they threw last year. He also had those pitchers fill out a questionnaire to determine whether they were morning or evening people.
The morning people had a lower ERA during games that started before 7 p.m. (the standard start time for an evening game)--their average ERA was 3.06, compared to 3.49 for the night owls. The reverse was true of night games, though the effect was less evident.
So perhaps the Chicago Cubs should dig up some rise-and-shine types to pitch all those afternoon games at Wrigley Field, while the New York Yankees would be better served by a staff of night owls hurling those never-ending games
against the Red Sox.