Situations like that are one reason a few coaches such as the 49ers' Kyle Shanahan don’t allow their quarterbacks to wear wristbands. He gives his quarterback the whole play call via the headset.

Let's go with play No. 45: "G [Gun] BROWN RT [Right] 74 HOSS X-FOLLOW" Those six components establish the formation, the pass protection, and the routes the receivers are to run. Formation: "Gun ...