They still do it the old-fashioned way, before the tiebreaker system was implemented. I checked to see if the Mets hold an advantage over the Diamondbacks, and for the moment at least, they don't. The second level of tiebreakers is the teams' record against their division opponents. The Mets are 23-20 (.535) against the Braves, Phillies, Nationals, and Marlins. The Diamondbacks are 22-19 (.537) against the Dodgers, Padres, Giants, and Rockies. Hopefully this won't matter, but if it does, it may end up being very close.