North Jersey would work. i've joked about the Raritan Bay Rays, but you could still split New York metro area 3 ways and have the 3 largest markets after accounting for other split markets. TV would love it. Basically, this would give Manhattan, the Bronx, and Westchester and Fairfield to the Yankees, Long Island to the Mets, and Staten Island and the rest of the populous part of Northern New Jersey to the Rays. It is to the benefit of the rest of baseball, just as splitting of Washington from Baltimore made sense for MLB. As for the Yankees and Mets, after some revenue sharing concessions and subsidies for their stadiums, they would likely play along. I don't see this as having much of an impact on the Mets, and while most of it would come out of the Yankees, there probably is a number or a deal that makes it work. Relax the luxury tax, split their revenue sharing burden with the Rays, etc...