Complex sentence: The Bills began playing in 1987 as the AA affiliate of the Cleveland Indians, became an affiliate of the Seattle Mariners in 1997, and played their final season in 1991 as part of the New York Mets organization.
Split into simpler sentences: The Bills began playing in 1987 at the AA affiliate of the Cleveland Indians. Their final season was play in 1991 as part of the New York Mets organization.