It’s rare that a young team’s growth is as linear as this USC football team’s has been.

In the first four games, the Trojans repeated many of the mistakes of an uneven 2010 season. They struggled to put away inferior teams and then couldn’t get out of their own way in a chaotic, emotional loss at Arizona State.

Since then, it’s been one step after the other back to the USC of old.

Just as in the glory days of Pete Carroll, the Trojans learned to bury teams whose talent didn’t measure up and to trade punches with the conference bullies. It all culminated on a cold, resonant night in Eugene, Ore., when USC knocked Oregon out of the title hunt and reclaimed its place as a Top Ten power.

Along the way, we’ve seen the emergence of one of the most efficient quarterbacks in school history, Matt Barkley, the dominance of two brilliant young receivers, Robert Woods and Marqise Lee, and the steady improvement of Monte Kiffin’s defense.

Strengths

Dangerous duo: If you’re going to avoid embarrassment against USC, you have to figure out some way to contain Woods. Just a sophomore, he’s one of the most complete receivers in the game and one of the nation’s most effective weapons.

In the past few games, Woods has been playing despite painful injuries to his shoulder and ankle. Somehow, it hasn’t slowed down the offense because Lee has been just as dangerous with the ball in his hands. If you leave either player in single coverage, you’re bound to feel the pain. Barkley found Lee on a 59-yard deep strike to open the scoring against Oregon and establish his dangerous tandem early.

Precision and Patience: Barkley made some throws against Oregon that were reminiscent of the best quarterbacks in the NFL, pinpoint strikes over a linebacker and into tight spots. What makes him such an elite talent, though, is his presence in the pocket, calmly working through his progressions amid the chaos of rushing defenders.

He looked off his primary target and found tight end Randall Telfer with a short TD pass that proved to be the decisive score against Oregon.

Tackling: Even after facing one of the most explosive running teams in NCAA history, Oregon, the Trojans boast the No. 16 rushing defense in the nation. Opponents are averaging just 3.6 yards per attempt against a defense that finally has started to grasp what Monte Kiffin and Ed Orgeron have been preaching.

Unlike in 2010, when the coaches tried to nurse a depleted roster through the season, the players worked on tackling all through fall camp and the difference has been eye-opening. Oregon didn’t score in the first quarter, in large part because the first USC tackler brought down his man.

Weaknesses

Air cover: The Trojans finally found a cornerback capable of locking down an elite receiver in sophomore Nickell Robey, who makes up for his lack of stature with elite speed and quickness, but they remain susceptible to good quarterback play.

The Trojans rank 100th in the nation in passing defense, allowing more than 260 yards passing per game. That’s in part because they play in an aerial league, but a lack of depth in the secondary has shown throughout the year. Safety T.J. McDonald is among the Trojans’ best players, but his propensity for illegal hits has cost the team at some key moments.

Ground game: For a school with a reputation for the flashiest running backs in the nation, USC hasn’t had an elite tailback since Reggie Bush and LenDale White left campus. At times, Marc Tyler and Curtis McNeal have provided a semblance of the thunder-and-lightning approach that works so well in this offense, but at other times a good ground game has been slow to emerge.

Considering USC might have the best tackle in the nation in Matt Kalil, the mediocre running game seems to reflect a lack of explosive runners. Just imagine if De’Anthony Thomas hadn’t broken his verbal commitment and bolted for Oregon.

Ball control: One of the trademarks of Caroll’s defenses was an ability to pry the ball from an opponent. You see flashes of ball hawking from these guys -- Robey has had some clutch interceptions and Nick Perry batted the ball from Darron Thomas’ hand on Saturday -- but not a consistent ability to force turnovers.

The Trojans have actually lost more turnovers, 18, than they’ve gained, 16, which could mean they’re even better than people realize.