Any coach on any level can use this book as a resource to install a complete defensive system. The book establishes an easy-to-understand vocabulary to describe an opponent's personnel, personnel groupings, formations, shifts, and motions. It also establishes a defensive vocabulary and system, and illustrates how positions are named, huddle procedure, substitution packages, gap labels, and alignment labeling. Featuring nearly 700 diagrams, the book also describes and illustrates fronts, base zone coverages, eight-men-in-the-box man coverages, stunt coverages, peel blitzes, goal line defense, situational defensive football (including time-affiliated situations such as Big Ben defense, four-minute offense, and two-minute offense), kick safe defenses, how to defend surprise formations such as the swinging gate, and much more. Positional technique play is also covered: defensive line play, linebacker play, and secondary play. Also included are tips on how to plan and implement a defensive practice plan and drills, which are tailored to the schemes and strategies included in the playbook.