Complex sentence: The Mets would advance to their first 2000 World Series since 1986, where they would meet their crosstown rivals, the New York Yankees in the first Subway Series to take place since 1956.
Split into simpler sentences: The Mets would advance to the 2000 World Series, their first appearance in the World Series since 1986. They would meet their crosstown rivals, the New York Yankees in the first Subway Series to take place since 1956.