In the 1968 college football season, the system of "polls and bowls" changed. The Associated Press returned to its pre-1961 system of ranking the Top 20 rather than the Top 10, and voted on the national champion after the bowl games, rather than before. During the 20th Century, the NCAA had no playoff for the college football teams that would later be described as "Division I-A". The NCAA Football Guide, however, did note an "unofficial national champion" based on the top ranked teams in the "wire service" (AP and UPI) polls. The "writers' poll" by Associated Press (AP) was the most popular, followed by the "coaches' poll" by United Press International) (UPI). In 1968, the UPI issued its final poll before the bowls, but the AP Trophy was withheld until the postseason was completed.