Football can be an extremely complicated sport. If you’ve seen an NFL playsheet or listened to a quarterback call a play, you know what I’m talking about. It wouldn’t be uncommon to hear something to the effect of “Trips right, Jet motion, Y option, Z out, X Banana, Power Left”, which means depending on the look to could be a run left, a pass right, or a give to the jet sweep.
Coaches and players will pour over film to discover tendencies, watch how a certain player will run a certain route in a certain situation and get a feel for the other team’s personnel.