what decides home field advantage for world series
World Series Beginning in 2017, home field advantage in the World Series will be awarded to the league champion team with the better regular season win-loss record.[26]If both league champions have the same record, the second tie-breaker would be head-to-head record, and if that does not resolve it, the third tie-breaker would be best divisional record.
Major League Baseball tie-breaking procedures One-game tiebreakers are played between teams tied for a division championship or a league's second wildcard berth. These games are to be played the day after the season is scheduled to end. Home-field advantage is determined using the rules listed below ("Breaking Ties Without Playoff Games").