Home-field advantage isn't just about knowing your ballpark's quirks, or sleeping in your own bed. It's also about keeping your circadian rhythm right.

With all those MLB teams flying around, sleep expert Christopher Winter wanted to know if jet lag throws off performance. So in 2008 he looked at travel patterns of teams, figuring it took them one day to adjust fully for each time zone traveled. He found that most of the time, the opposing teams are equally adjusted to the time zone in which they're playing. But when they're not, the advantage emerges.

If one team has the adjustment advantage by a day or two, the benefit is small: They win 52 percent of the time. But, if one team has a three-day advantage over another, they win 60 percent of the time. So, if the Angels fly across the country to New York to play the Yankees (who are already adjusted to Eastern time), it's advantage Yankees. For the first game, at least.