This Freakonomics Radio episode investigates the decline of running back salaries in the NFL. The podcast blends interviews with a Harvard economist, former NFL running backs, a sports data scientist, and a sports agent, alongside co-hosting segments between Stephen Dubner and the economist. The discussion explores several factors contributing to this decline, including the increased value of passing plays due to rule changes and analytics, the impact of the 2011 collective bargaining agreement on rookie contracts, and the inherent physical toll on running backs leading to shorter careers. For example, the average salary for starting quarterbacks is over $30 million, while it's only $6 million for running backs. The episode concludes by considering whether this trend is cyclical or permanent, highlighting the ongoing debate about the value of running backs in the modern NFL.