In the constantly evolving world of college football, how long can one team so fixed in its ways stay on top?

Every year the Trojans must endure a roster overhaul, a change that requires USC coach Pete Carroll to tinker his style ever so slightly. But when the philosophy remains the same year in and year out, the striking similarities between Trojan teams past and present outweigh the subtle differences.

“We have a great challenge ahead of us this year, but we’re going about it in the same way,” Carroll said. “This is nothing new for us.”

There has been little revolution in USC football since the program first replaced Reggie Bush, Matt Leinart and the stars of its last championship-level team. That’s probably fine by Carroll, who has preached the same message of eliminating mistakes on offense and creating turnovers on defense to guide his team to seven straight Pac-10 titles.

What has changed during the course of USC’s run is everything that surrounds the program. Washington State, the last team to beat out USC for a spot in the Rose Bowl, now sits at the bottom of the conference. Cal, once a perennial flounder in the standings, has turned itself into one of USC’s closest competitors.

With new commissioner Larry Scott, the Pac-10 is looking to reinvent itself in order to put the conference in the same discussion of college football’s elite with the SEC and the Big 12. For the other nine teams in the conference, the mission starts with knocking Carroll and Co. off their pedestals.

Even though USC has been the class of West Coast football since 2003, the Trojans have needed some help recently to keep their run going. It took an Oregon State loss to Oregon in the final week to assure that USC won the Pac-10 outright and would go to the Rose Bowl. The Trojans’ run looked like it was finally over in 2007 after losing to Oregon, but a late-season collapse by the Ducks on the heels of an injury to Dennis Dixon gave way to another conference title for USC.

“USC has set a very high standard, but it’s getting harder for them to match up team for team in this conference,” Arizona coach Mike Stoops said at Pac-10 media day. “Each team is getting better and giving USC their best shot every time, and it’s getting harder.”

That’s not to say that pessimists predicting an end of an era will be patting themselves on the back come bowl season. Only four of the 32 voters in the preseason Pac-10 poll dared to tab a team other than USC as tops in the Pac-10, and the Trojans should be favored in every game they play this season.

What an improved conference and challenging schedule does mean for USC, though, is that there’s a smaller margin of error. But if that can keep the Trojans on their toes, it might be the additional spark the team has been looking for over the past three years.

Even if the Trojans have proved they are the best of the Pac-10, they have yet to demonstrate they can navigate the conference schedule without having an out-of-body experience against an unexpected foe.

“I don’t think there’s a lot of magic to beating [USC],” said Oregon State coach Mike Riley, whose team has taken down the Trojans in two of the last three meetings. “Our defense had to disrupt them and we had to play a really, really efficient game. Lasting against those guys is the hardest part.”

Hmm, sound familiar to anyone? Pac-10 coaches are finally adopting the defensive-centered, run-oriented agenda that took the Trojans to the top and kept them there for so many years. The conference of quarterbacks has become the center for smashmouth football, with almost every coach at Pac-10 media day insisting that any competitive team will need to be able to hold on to the ball and stop teams up front on defense.

The rest of the conference catching up to USC is great for Pac-10 football, and it might even be good news for USC. Complacency has been as big of an adversary as anyone on the schedule, but the challenges awaiting the Trojans this season might help eradicate it. Four of the first six games are on the road and the away games provide the toughest tests of the season.

If USC is undefeated by November, a month in which Carroll has not lost since arriving at USC, they face four teams likely struggling to gain bowl eligibility.

Previous losses have kept USC out of the national championship, but a loss this year could give another Pac-10 team the opening they’ve been waiting for the last seven years.

“I don’t think we’re at the end of this run. I’d like to think we’re somewhere toward the middle,” Carroll said when asked to muse about how far he has brought the program since his arrival. “The challenge for us now is to create the discipline to stay on task and stay with what has made us.”

With an improved Pac-10, Carroll’s message might be as important as ever. If his team is able to demonstrate that commitment for 12 Saturdays during the regular season instead of 11, it will be making the last step forward that has eluded it for the last three years.

Call it the final stage of the evolution.

“Tackling Dummy” runs Tuesdays. To comment on this article, visit dailytrojan.com or e-mail Michael at middlehu@usc.edu.