Cover 2 has been a staple in NFL defenses since the 1970s. Photo courtesy of Wikimedia. DAVID JACOBS | ASSISTANT SPORTS EDITOR | drjacobs@butler.edu  Overtime, or “OT,” is an opinion column series where the Collegian takes national sports headlines or polarizing topics and gives them a Butler-centric angle. When the 1970s Pittsburgh Steelers terrorized offenses…