It's no secret Yankees fans outnumber Mets fans in our backyard. The size of the disparity may surprise you: more than 3-to-1.

The surprising findings come from Ben Blatt of the Harvard Sports Analysis Collective, who mined “likes” on Facebook to measure allegiance to the local sports teams among fans in New York City, Westchester, Long Island and northern New Jersey. The data covers a representative sample of 6 million Facebook users.

The Yankees’ popularity dominance over the Mets is one of the most striking takeaways from the numbers. The Bombers — no shock — were the most supported of any New York sports team, tallying a total of 1,096,400 likes. But the next most popular, the Giants, had more than 36 percent fewer at 694,280. The Knicks were third at 670,880.

The Jets are next, though there’s a big drop to 425,740. Then come the Mets at 353,580 — less than a third of the Yankees’ total.

The Yankees garnered the majority of the support over the Mets in every town, county and zip code analyzed on a more micro scale. The Amazin’s had the most traction in Floral Park, at 41.6 percent of the likes for a local baseball team. The strongest pro-Yankees area was Morris County, where 87 percent of the breakdown had a pinstripe pattern.