Gus is going back to being a football coach instead of a CEO, so we’re going back to the book he turned to when he first became a head coach in high school.
In the last chapter, Tubby Raymond laid out how to categorize defenses and label their parts. Basically, there are 3-deep and 4-deep defenses, and they all have a force player and a contain player, the two defenders he suggests focusing on.
In this chapter, Raymond uses those basic defenses to show the reader how offensive plays can be called to force a defense out of position, attack all parts of the field, and react to the inevitable defensive reactions.