Oh, the difference a year makes.

A year ago, USC ranked No. 25 in the Associated Press’ preseason college football poll. In USA Today’s poll, the Trojans were absent because of sanctions.

One 10-2 season and one upset of Oregon later, the Trojans now rank in the top three in every preseason poll imaginable, including a No. 1 ranking in the AP poll. With senior quarterback Matt Barkley leading the offense and senior safety T.J. McDonald in charge of the defense, USC is poised to make its first legitimate national championship run since the 2008 season.

Expectations are nothing new to USC squads; heck, the Trojans contended for a national championship every year from 2003 to 2008, starting each season somewhere in the preseason top-10.

Alas, the Trojans haven’t won the BCS trophy since the 2004-2005  season (although the BCS title was taken away) despite lofty expectations since.

Despite Carroll’s stellar 97 wins in his nine-year USC tenure (ignoring the vacated wins), the Trojans appeared in only two national title games. All those other seasons saw USC stumble once or twice and finish on the outside looking in.

In fact, since 2002, only one team has started the season ranked No. 1 and finished there as well: The 2005 Orange Bowl-winning Trojans. Only three teams in the last 26 years have gone wire to wire. College football is an unpredictable sport, and preseason hype hardly guarantees success.

Take 2002: Miami, who had won the title the previous year, headlined the AP Poll. Oklahoma, Florida State, Texas, Tennessee, Florida and Colorado sat near the top as well. At season’s end, Ohio State, who started as No. 13, was the champion and Miami finished second while Oklahoma and Texas finished with two losses apiece. Florida State and Colorado, meanwhile, both went 9-5, finishing No. 21 and 20, respectively.

The Trojans have been let down before in terms of expectations, as well. Barkley’s freshman season saw the Trojans start at No. 4 in 2009 after winning 12 games the year before. They lost four games and stumbled to a No. 22 finish.

College football has a funny way of surprising us year in and year out. Last season it was Baylor, led by quarterback Robert Griffin III, triumphing over Oklahoma for the first time ever en route to a 10-win season. USC also surprised most people last year by winning 10 games and defeating Oregon on the road.

As fans and alumni know, USC is no stranger to the hype machine, but the team doesn’t seem too worried about preseason expectations. Instead, they are more concerned with the present and what they can do themselves.

It is pretty evident from the sign on Howard Jones Field that reads “Locked in” that it doesn’t matter what happens in publications or in preseason polls, or any outside sources for that matter: It is about doing what you can during practice and focusing on each game and each week.

Coach Lane Kiffin isn’t likely concerned with what publications have to say. He is, however, concerned with what happens on the field. His open gripe with the Pac-12 officiating last season after the Stanford game over what he believe cost the Trojans a chance to win in regulation is proof that his main priority is what occurs on Saturdays in the fall, not what happens during the summer.

Though that might mean there are expectations of a national title internally, USC is more concerned with getting better and ignoring what outsiders say. Because, as we know, what analysts and pundits think really doesn’t mean much. The team determines its own success.

So a word of the wise to those expecting instant magic and gratification from the 2012 USC Trojans: You can be excited, but don’t book your flight to Miami for the national championship game quite yet.

As we have seen, the Trojans could finish anywhere on the spectrum. They could be national champions as many expect them to be; they could also finish with two or three losses. Or they could finish ranked in the 20s with four or five losses. No one knows. That is the beauty of college football: Every week has potential for an upset that can turn the BCS on its head.

Preseason polls are just barometers for what we can expect — they are by no means an exact science. It might be “national championship or bust” here in Troy, but there is no reason to believe that “bust” isn’t possible, if not probable, based on history.

A high preseason ranking can easily turn into a four-loss season. Games are won in September and October, not in July and August.

“Goal Line Stand” will run Mondays. If you would like to comment on this story, visit DailyTrojan.com or email Michael at katzml@usc.edu