Book excerpt: "What economic rules govern sports? How does the sports business differ from other businesses? [This book examines] the fundamental economic relationships shaping modern sports. Focusing on the ways that the sports business does and does not overlap with economics, the book uncovers the core paradox at the heart of the sports industry. Unlike other businesses, the sports industry would not survive if competitors obliterated each other to extinction, financially or otherwise--without rivals there is nothing to sell. Playbooks and Checkbooks examines how this unique economic truth plays out in the sports world, both on and off the field"--Publisher marketing.