FILE - In this Feb. 23, 2016, file photo, Kansas City Royals&#039; Jarrod Dyson yawns as he waits to field balls during spring training baseball practice in Surprise, Ariz. Researchers say they&#039;ve documented an unseen drag on major league baseball players that can wipe out home field advantage, make pitchers give up more home runs, and take some punch out of a team&#039;s bats. The culprit: jet lag. (AP Photo/Charlie Riedel, File)