Baseball Time of Day Stats

Biological clocks may impact baseball players

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Yogi Berra, who has always had a unique flair for the English language, once said, "Baseball is ninety percent mental and the other half is physical."  Wonder what he would say about new data that shows the time of day a ballplayer bats may impact his batting average?

Principal investigator and lead author Dr. W. Christopher Winter, medical director of the Martha Jefferson Hospital Sleep Medicine Center in Charlottesville, Va. reports that trends indicate that morning-type batters progressively got worse as the day wears on and evening-type batters get progressively better as nighttime approaches.

"Athletic performance may depend on the time of day."

Winter explains that it's a new way to look at and possibly evaluate athletic talent. The current stadards in place for selecting an athlete to stay on the bench or play include rest, previous success against the opponent and handedness. Now, the time a game is played should factor into the equation as well.

He also explains that the data is not statistically significant due to low number of ballplayer participants, however, MLB managers are perking up their ears with this new information which may enhance player selection on daytime and nighttime games.  

The study assessed 16 players from seven MLB teams. Sleep preference for each ballplayer was determined using a version of the Morningness-Eveningness Questionnaire (MEQ), which categorizes a person's tendency to be either a morning kind of guy who prefers to go to bed and wake up early, or an evening kind of guy who prefers to stay up late at night and wake up late in the day.

Nine ballplayers were found to be evening kind of guys, and seven were found to be morning kind of guys. The ages of both groups were the same. 

The study assessed players' statistics from the 2009 and 2010 seasons, which had  batting averages for 2,149 innings from early games, 4,550 innings from afternoon games and 750 innings from evening games.

Results were as follows: "Morning guys" had a higher batting average (.267) than players who were "Evening guys" (.259) in games that started before 2:00, but the evening guys had a higher batting average (.261) than the morning guys (.252) in mid-day games that started between 2 p.m. and 7:59 p.m. This trend continued into the nighttime games  for evening guys continued to be strongerin late games that began at 8 p.m. or later with a .306 batting average and morning types maintained the same .252 average.

While the study is very small and needs verification with a larger study, the Major League Baseball teams are very interested in these results.

Reviewed by: 
Review Date: 
June 14, 2011
Last Updated:
June 17, 2011