I don’t understand the rules of Overtime.

[daviswr7]

Forgive all of my ignorance, but here’s a question:

If both teams are allowed the football guaranteed at Overtime, why is there a clock? As I sat there and watched the Green Bay Packers scramble last night to get a play called, I thought to myself what happens if the team that gets the ball first rattles off a nine minute and 55 second Drive????The other team only gets 5 seconds? I don’t get it. Somebody needsto explain it to me. Apologies for my ignorance. There should be no clock in overtime. Each team should get a untimed possession and that is that. Or maybe I’m wrong. Please help.