He must average 3.1 plate appearances per game the cubs have played. Starting the night, Barrett was 14 PA shy of qualifying. There is a little known exception to the minimum 3.1 plate appearances per game (502 PA in a season---unless a game was cancelled), which is: if a hitter leads the league in batting and does not have sufficient plate appearances, BUT still leads the league in batting after imputing an 0-(#of plate appearances need to get to 502) to his ABs, he is awarded the batting title.