Complex sentence: With McGraw, the Phillies had two 101-win seasons and their first World Championship, while the Mets had two mediocre seasons and then descended to the bottom of the National League for seven years.
Split into simpler sentences: With McGraw, the Phillies had two 101-win seasons and their first World Championship. The Mets, meanwhile, had two mediocre seasons, then descended to the bottom of the National League for seven years.