We’ve all heard it: A true freshman has never started a season at quarterback for the Trojans.

But that will all change on Saturday, when No. 4 USC opens its season in historic fashion against San Jose State at the Coliseum in front of 90,000 screaming fans.

When Pete Carroll chose Barkley to be his starter over redshirt sophomore Aaron Corp one week ago, many were shocked. Even Barkley admitted he was caught off guard.

“I was speechless when coach told me,” the 18-year-old said.

And even Carroll was at somewhat of a loss when trying to explain why he chose a freshman quarterback rather than going with his usual pick of a veteran to man the offense.

“I can’t explain how a guy this young and this new could do that, but he’s done it,” the coach said.

Carroll and his coaching staff clearly saw something they’d never seen in a freshman quarterback before. And I’m talking about more than his 6-foot-3, 220-pound frame and rifle of an arm.

So now Barkley is set to start the season for the Trojans. And for the first time since a true freshman named Carson Palmer took the over the starting quarterback job from Mike Van Raaphorst during the last five games of the 1998 season, the quarterback position at USC may be occupied by one man for four seasons.

So this brings up an interesting topic. If Barkley develops the way the coaches expect him to, he will have three to four full seasons at quarterback before entering the NFL draft.

So while many people are focusing on the history Barkley will be making when he takes his first snap Saturday, I’d rather look at the potential history Barkley could make when he takes his last snap in what could be four years from now.

Let’s take a look at what I consider the three gaudiest quarterback records and see what Barkley’s odds are of reaching them. This is, of course, assuming Barkley stays for his senior year with USC, just like Palmer, who holds most of USC’s passing records.

The first number I look at is 11,818. That’s the record Palmer holds for most yards gained passing as a Trojan. It’s also a Pac-10 record.

If Barkley stays a full four years in college, he would need to average 2,955 passing yards per season to pass Palmer as the all-time USC and Pac-10 leader.

Just to put that number in perspective, look at how quarterbacks have fared under Carroll’s system during their first years in the starting role.

Last season, Mark Sanchez threw for 3,207 yards. In 2006, John David Booty threw for 3,347 yards. And in 2003, Matt Leinart threw for 3,556 yards.

In Palmer’s first full year as a starter in 2000, he threw for 2,914 yards.

Simply put, the record is within reach.

Palmer also holds the school and Pac-10 record for the most passes completed during a career with 927.

In four years, Barkley would need to average 232 completions to top that record.

Sanchez completed 313 passes in 2008, Booty completed 269 passes in 2006 and Leinart completed 255 passes in 2003. All of those numbers are higher than what Barkley needs to reach each season.

Palmer himself only completed 228 passes his first full year, slightly lower than the 232 completions Barkley needs to average, but Palmer ended his senior year in 2002 with a whopping 309 completions.

Barkley, like Palmer and all young quarterbacks, will be expected to gradually improve each season as well.

That puts 938 in reach for Barkley.

And the last number I want to look at is passing touchdowns.

Leinart set the record at 99 during his time in college, both a USC and Pac-10 record.

It’s not hard to do the math here. If Barkley averages 25 passing touchdowns over the next four seasons, he will reach the magical number of 100 only attained by six other college quarterbacks in the history of the sport.

So one more time, look at the numbers.

In each of their respective first full seasons starting, Sanchez threw 34 touchdowns, Booty threw 29 touchdowns and Leinart threw 38 touchdowns.

Again, all of these numbers are higher than what Barkley needs to average in four seasons. The only difference for those previous quarterbacks is they did not have the opportunity to start four full seasons at quarterback for USC.

Barkley will.

Just by breaking it down, it’s easy to tell there is a solid chance, if Barkley stays, that he will own arguably the most prestigious of USC quarterback records when all is said and done.

So when you step into the Coliseum or turn on the television to watch the game Saturday, you will be witnessing history right away as Barkley takes his first snap.

But remember, it may not be the last time the true freshman puts his name in the record books.

“Soft Hands” runs every other Thursday. To comment on this article, visit dailytrojan.com or email Jon at jhaber@usc.edu.