1) Mets rival: The case for the Atlanta Braves
The Atlanta Braves weren’t always a National League East rival of the Mets. This didn’t stop the rivalry from kicking off to new heights in 1969. The two played in the first ever NLCS with the Mets coming out on top.
They’d see each other in the postseason again in 1999 with the Braves winning that one. It ended a decade of dominance from the Braves which would continue into the 2000s.
Older Mets fans might not agree with the Braves being the biggest rival of all. In the 1970s and 1980s, clashes between the two weren’t so notable. It wasn’t until MLB’s realignment that put them together in the NL East in 1995 when we began to care about where Atlanta was in the standings.
The Braves have easily been the best time in the division since 1995 when the five teams currently in there were set—the Washington Nationals converting from being the Montreal Expos included. More often than not, it’s the Braves the Mets need to chase. With all of those years built up in the 1990s and 2000s, it’s hard for fans of a certain age to think of anyone else as the biggest rivals of the Mets.
You may have never legitimately met a Braves fan in your entire life if you’ve stayed in the Northeast. This doesn’t stop us from knowing they are indeed the biggest Mets rival.