For 52 years, Boston was a two-team Major League city, home to both the Red Sox and the Braves. This book focuses on the two teams' period of coexistence and competition for fans. The author analyzes the Boston fan base through trends in transportation, communication, geography, population and employment. Tracing the pendulum of fan preference between the two teams over five distinct time periods, a deeper understanding emerges of why the Red Sox remained in Boston and the Braves moved to Milwaukee.