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The USC Trojans and the Texas Longhorns finished the regular season as the only undefeated teams in Division I-A and consequently met in the Rose Bowl to play for the national title. Texas defeated USC largely due to the performance of quarterback Vince Young, who gained 467 yards of total offense and ran for three touchdowns. The Longhorns won their first national championship since 1970, and their first consensus national title since 1969.
Rule changes
*After the Big Ten Conference's 2004 experiment with instant replay, its use was expanded to all but the Sun Belt and the WAC conferences in Division I-A. The rules varied between conferences (including the use of coaches' challenges similar to the NFL in the Mountain West Conference) until the NCAA standardized the rules in 2006. Replay was also permitted in bowl games and, provided the visiting team agreed to its use, in non-conference regular season games.
The protection for a receiver who signals a fair catch includes situations when the ball is muffed until it hits the ground.
Penalties for spearing or similar hits in which the tackler leads with the crown of the head are enforced regardless of the "intent" of the tackler.
The penalty for leaping on field goals/PATs now states it is a foul if a player lined up more than one yard behind the line of scrimmage jumps and lands on players of any team trying to block the kick. If lined up one yard or closer to the line, it is not a foul.
Eliminated the "legal clipping zone"; hits from behind below the knee are prohibited anywhere on the field.
Provided for officials a specific list of acts by players considered unsportsmanlike conduct, including the "throat slash", high stepping and diving into the end zone unchallenged among others. Spontaneous celebrations by players are allowed provided they are not prolonged, taunting, or bring attention to themselves.
Boston College left the Big East to become the 12th member of the Atlantic Coast Conference (ACC), allowing the league to split into two divisions and hold an annual championship game.
Longtime head coaches Barry Alvarez of Wisconsin and Bill Snyder of Kansas State, both of whom took struggling programs to national prominence during their tenures, retired. Dan Hawkins, having helped make Boise State a powerhouse in the Western Athletic Conference, left the Broncos to coach struggling Colorado.
Regular season top 10 matchups
Rankings reflect the AP Poll. Rankings for Week 8 and beyond will list BCS Rankings first and AP Poll second. Teams that failed to be a top 10 team for one poll or the other will be noted.
Heisman Trophy voting was primarily for three players: Reggie Bush, Matt Leinart (who won the trophy in 2004) and Vince Young. Bush won the trophy, with Young (who helped Texas win their first national championship since 1970) second in the voting:
In June 2010 the NCAA ruled that Bush had received "improper benefits", violating NCAA policy. On September 14, he announced in a statement from the New Orleans Saints that he would forfeit his 2005 Heisman Trophy. Runner-up Vince Young said that he would not accept the trophy if Bush forfeited it. On September 15, the Heisman Trust announced that the 2005 trophy would be vacated and there would be no winner for the season. Bush's Heisman win would be reinstanted on April 24, 2024, with the Heisman Trophy Trust citing "enormous" changes in college athletics, including the introduction of name, image and likeness (NIL) a few years prior.
Texas team and coach Mack Brown with President George W. Bush after winning the 2005 national championship