USC entered the 2005 season as the clear favorite to win the national championship. The Trojans were the easy choice in 2004 too. Oklahoma and Ohio State were the top picks in 2003. But this season is different. No team stands out as a title favorite.
Before the wide-open race gets underway, take a quick look at 10 top contenders to reach the BCS National Championship game in Glendale, Ariz.
Why they'll be in Glendale: RB Kenny Irons. Brandon Cox's experience at quarterback. Eight home games, including LSU, Florida and Georgia going to the Plains. Great coaching staff got better with the addition of defensive coordinator Will Muschamp.
Why they won't: A potential academic scandal looms over the program after the New York Times questioned the offering of directed reading classes to several football players in 2004. Two top linebackers suspended for the first three games. Must replace both offensive tackles and two top receivers.
Why they'll be in Glendale: Coach Urban Meyer has stockpiled receivers and quarterbacks for his spread offense. The Gators have owned Georgia, their main competition in the SEC East, for most of two decades.
Why they won't: Quarterback Chris Leak still hasn't won a championship and will be looking over his shoulder at freshman Tim Tebow. Leak isn't the right fit for Meyer's offense. The schedule is daunting with road games at Tennessee, Auburn and Florida State and home games against Alabama and LSU, along with the Georgia game in Jacksonville.
Florida State Seminoles
Why they'll be in Glendale: QB Drew Weatherford should be better in his second season as a starter. The receiver corps is still very deep and talented. The Seminoles don't play Virginia Tech and Georgia Tech from the Coastal Division and they host Clemson and Boston College in Tallahassee.
Why they won't: The defense lost two key linebackers and its entire secondary. Lorenzo Booker will have to carry the load now that Leon Washington has left. The offensive line still has questions after injuries decimated the unit last season.
Why they'll be in Glendale: Former coach Nick Saban left successor Les Miles a wealth of talent. Free safety LaRon Landry might be the SEC's top defensive back. The Tigers play eight home games.
Why they won't: JaMarcus Russell still hasn't blossomed at quarterback. Two tailbacks are coming back from knee injuries. The receivers have underachieved. Top two offensive linemen are gone, along with three stars on the defensive line.
Notre Dame Fighting Irish
Why they'll be in Glendale: Brady Quinn. Jeff Samardzija. Darius Walker. Rhema McKnight. Victor Abiamiri. Tom Zbikowski. Charlie Weis. Need we say more?
Why they won't: A pass defense that ranked 103rd in the country last season. Road games at Georgia Tech and USC. Home games against Penn State, Michigan and UCLA.
Ohio State Buckeyes
Why they'll be in Glendale: Quarterback Troy Smith. Running backs Antonio Pittman and Chris Wells. Receiver/kick returner Ted Ginn Jr. All but one offensive lineman is back. They get Penn State and Michigan at the Horseshoe.
Why they won't: No A.J. Hawk or Bobby Carpenter or Anthony Schlegel. All four defensive backs are gone too. The Buckeyes play at Texas and Iowa. They've got to force more turnovers and give away fewer, after ranking 104th in the country in turnover margin in 2005.
Why they'll be in Glendale: The Sooners have Adrian Peterson, the country's best running back, and a stingy defense led by linebacker Rufus Alexander. Oklahoma will be hungry after last season's humbling 8-4 record and plays Texas Tech at home.
Why they won't: The Sooners got Bomared. Starting quarterback Rhett Bomar and sophomore offensive guard J.D. Quinn were kicked off the team last week for breaking NCAA rules. Oklahoma turns to senior Paul Thompson, who will start at quarterback after moving to receiver in 2005.
Why they'll be in Glendale: With Bomar gone, Texas seizes control in the Big 12 South. The Longhorns are deep at running back and receiver. They play Ohio State in Austin, one of seven home games, and face Oklahoma in Dallas.
Why they won't: One of two freshmen, Colt McCoy or Jevan Snead, tries to replace Vince Young, who bolted for the NFL after leading the Longhorns to a national title. Three All-Americans -- offensive tackle Jonathan Scott, guard Will Allen and safety Michael Huff -- also are gone.
Why they'll be in Glendale: Pete Carroll hasn't been recruiting bums. Even though the Trojans lost Matt Leinart, Reggie Bush, LenDale White and a score of other top players, they'll reload with players from consecutive No. 1-ranked recruiting classes. They play Nebraska, Arizona State, Oregon, Cal and Notre Dame at the Coliseum.
Why they won't: Quarterback John David Booty has a bad back, and backup Mark Sanchez had off-field problems. Receiver Dwayne Jarrett still hasn't been cleared to play by the NCAA after he was ruled ineligible for living with Leinart on the cheap.
West Virginia Mountaineers
Why they'll be in Glendale: Quarterback Pat White and tailback Steve Slaton are the most dangerous combination in college football and coach Rich Rodriguez's spread attack takes advantage of their speed. The Mountaineers play in the Big East.
Why they won't: The Mountaineers play at Louisville on Thursday, Nov. 2 (ESPN, 7:30 ET) in a game that should decide the Big East title. Aside from that game, their schedule is too soft to be taken seriously.
Mark Schlabach covers college football and men's college basketball for ESPN.com. You can contact him at firstname.lastname@example.org.