the dead-ball spot. Jerseys must be replaced if the numbers are no longer readable. (Tear-aways were popular for backs & receivers, later prohibited) Mouthpieces are made mandatory starting with the 1973 season. Conference and program changes NCAA structure This was the last season for the "University" and "College" divisions. For the 1973 season, the NCAA created the three-division structure that exists today with teams and conferences designated accordingly: The University Division became Division I The College Division was subdivided into Division II and Division III Five years later in 1978, Division I was subdivided (for football only) into I-A and I-AA. In 2006, these were renamed Division I FBS and FCS, respectively. Many of the teams and conferences now in FCS (Big Sky, Ohio Valley, SWAC, Yankee) were initially in Division II and moved up to I-AA. Membership changes Program changes Stanford University officially changed their nickname from Indians to Cardinals in 1972; it became the singular Cardinal in 1982. The Gulf South Conference, now in Division II, began football play in 1972. September In the preseason poll released on September 4, two-time defending national champion Nebraska Cornhuskers was ranked first, followed by their Big 8 conference rival, Colorado. Next was Ohio State, Arkansas, and Penn State. On September 9, No. 1 Nebraska lost 20–17 on a late field goal to unranked UCLA at night in Los Angeles and dropped to tenth place. No. 2 Colorado beat California 20–10. No. 3 Ohio State was idle, and No. 4 Arkansas lost 31–10 to No. 8 USC in Little Rock. No. 5 Penn State had not begun its season but fell to sixth. No. 7 Alabama beat Duke 35–12 in Birmingham and reached the top five, as did No. 6 Oklahoma, which had not yet played a game but moved up two slots. In the next poll, USC received 13 first place votes, and Colorado and Oklahoma had 12 apiece, but USC had a narrow lead in points, 779 to Colorado's 769. The poll was led by No. 1 USC, No. 2 Colorado, No. 3 Ohio State, No. 4 Oklahoma, and No. 5 Alabama. September 16: No. 1 USC trounced Oregon State 51–6, and No. 2 Colorado was idle. No. 3 Ohio State blanked Iowa 21–0, and No. 4 Oklahoma shut out Utah State 49–0. No. 5 Alabama was idle, and No. 7 Tennessee took its place in the next poll following