In his book, Take Your Eye Off the Ball: How Watch Football By Knowing Where to Look, (Amazon Affiliate link) Pat Kirwan explains how a National Football League team constructs its gameplan each week.

Every NFL team has a playbook that’s about as thick the Manhattan phone book (Manhattan, New York, not Manhattan, Kansas). The playbook contains roughly a thousand offensive plays, and each play has variations, based formation.

So theoretically, every team has several thousand plays that could be used during a game. But not all the plays are included in the gameplan each week. Take a guess at how many plays are in the gameplan. Is it 200? 100? 75? The answer: about 40 plays.