Bill C’s annual preview series of every FBS team in college football continues. Catch up here!

Any program can succeed; some just have far greater margin for error. Within the Pac-12, as discussed in a recent Podcast Ain’t Played Nobody, we have some pretty good examples of this.

Oregon State has had minimal margin for error. A coach has to do very good things just to remain at a good level, and then he has to keep doing very good things. At USC, however, you merely have to be good to be very good.

USC Trojans Head coach: Helton (21-6, third year) 2017 record and S&P+ ranking: 11-3 (26th) Projected 2018 record and S&P+ ranking: 8-4 (15th) Five key points: Even decent coaches can have a good couple years at USC. Year 3 at the Coliseum tends to differentiate the excellent ones. It’s Helton’s third year. Outside of QB, it appears USC has everything it needs on offense. But ... QB is important, and we’ll see what either sophomore Matt Fink, RSFr. Jack Sears, or freshman JT Daniels has to offer. USC’s run defense cratered last year, but linebackers Cameron Smith and Porter Gustin could be the linchpins for improving while maintaining an excellent pass rush. Early-season trips to Stanford, Texas, and Arizona will define the season. Are we talking about another Pac-12 title run? More? An eight-win reset year? We’ll know by October 1.

Helton has been pretty good. In two years, the Trojans’ average S&P+ rating (plus-13.7) has slightly exceeded what it was in six years under Lane Kiffin and Steve Sarkisian (plus-13.5), and after beginning 1-3, he’s gone 20-3. His first USC team won the Rose Bowl, and his second won the Pac-12. The first QB to whom he hitched his ride, Sam Darnold, just got picked third in the NFL draft.

But the successes have almost made the rare failures harder to accept. Four of his six losses have come by at least 17 points — 52-6 to Alabama and 27-10 to Stanford in 2016, 49-14 to Notre Dame and 24-7 to Ohio State in 2017 — and that 1-3 start in 2016 was due in part to not being able to choose between Darnold and Max Browne at QB (which seems baffling in hindsight). His offense couldn’t build on 2016’s success last fall, and his second defense was far less impressive than expected.

There’s a dark side to top jobs. You only have to be good, but you’re also looked at with far more skepticism and for a far longer period of time. And because even decent coaches can succeed, it takes us a long time to get a truly accurate read.

Ted Tollner won the Rose Bowl in his second year at USC but lasted only two years beyond that. Larry Smith went to three straight Rose Bowls and put together top-10 finishes in his second and third seasons; he was 3-8 in year five and gone in year six. Lane Kiffin won 10 games in his second year and was run out of town a year and a half later.

We’ll learn a lot about Helton this fall. He and his staff will have as many blue-chippers as ever to sift through, but they have to figure out what went wrong on run defense, and on offense they have to replace not only Darnold, but also leading rusher Ronald Jones II and two of last year’s top three receivers (Deontay Burnett and Steven Mitchell Jr.).

Year three tends to separate wheat from chaff. John McKay and Pete Carroll won national titles in their third seasons, and John Robinson nearly did as well. If you’re betting on Helton’s tenure going one way or the other, which way do you lean?

Offense

USC’s offense was mostly awesome. The Trojans were efficient (12th in success rate) and packed big-play potential (seventh in gains of 20-plus yards per game), and while we paid a lot of attention to Darnold’s turnover problems, especially during the run-up to the NFL draft, those concerns were a bit overblown — the Trojans had poor fumbles luck, and nearly half of Darnold’s interceptions came in the first three games.

Still, there were glitches.

The Trojans suffered just enough negative plays to create too many third-and-longs. They were excellent at generating first downs before third down even came up, but their average third-down distance was 7.5 yards, 106th in the country. They were downright bad in the red zone. They averaged a paltry 4.2 points per scoring opportunity (first downs inside the opponent’s 40), 92nd in the country. This was never more of an evident problem than in the Cotton Bowl loss to Ohio State, in which they created seven scoring opportunities to the Buckeyes’ three but somehow managed seven points.

These are not guaranteed to improve, especially with a less experienced QB and skill corps.

But USC got the most important things — gaining yards on first down and creating scoring chances — right, and I’m guessing that will continue.

Blue-chipper Stephen Carr’s marginal efficiency (plus-1 percent) was nearly equal to Jones’ (plus-3 percent), and he gained at least five yards on a higher percentage of his carries (40 percent to Jones’ 39). And this was despite missing a good portion of the season with a foot injury — through four games, he was averaging 6.3 yards per carry, but he missed four games and averaged just 3.6 per carry the rest of the way.

Carr missed spring ball with a herniated disc, which meant reps for senior Aca’Cedric Ware (who had 122 yards against Arizona last year but otherwise averaged just 3.6 yards per carry) and sophomore Vavae Malepeai.

The Trojans had to replace three all-conference guys up front last year, but in 2018 they return two: second-teamer Toa Lobendahn at left tackle and honorable mention guy Chris Brown at left guard. A lot of last year’s glitches started up front, and that should be less of an issue.

It’s hard to worry too much about the receiving corps. Burnett and Mitchell were solid, combining for 1,758 yards, 8.7 yards per target, and a marginal efficiency of plus-13 percent. But sophomore Tyler Vaughns and junior Michael Pittman Jr. topped those per-target numbers (10.6 yards per target, plus-20 percent marginal efficiency), and there’s a giant cast from which to find a No. 3 target.

The primary question is whether the Trojans have a pass thrower. Sophomore Matt Fink (who completed six of nine passes as Darnold’s backup last year) and four-star redshirt freshman Jack Sears were the main competitors for the job this spring, and all-world freshman JT Daniels will join the battle in August.

This appears to be a battle of ceiling vs. floor. Sears and Daniels boast massive upside, and Sears does have the advantage of having been on campus for a year. But avoiding mistakes is key, and coordinator Tee Martin — quite the high-floor quarterback at Tennessee 20 years ago — will need to trust in one’s mistake avoidance in order to not the job to Fink, a three-star recruit who has been in the system the longest.

The skill corps is young but has already proved quite a bit, and the line is more stable. Martin should establish enough of a ground game to take a little pressure off of his inexperienced signal caller, and he knows what it’s like to succeed with a young QB (Darnold was a redshirt freshman in 2016). But until we know USC has a ready QB, not a whole lot else matters.

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Defense

USC’s defense caught fire about a month into 2016 and finished 20th in Def. S&P+, but it still had a few issues. The big plays were enormous, both via run and pass, the Trojans weren’t very good in the red zone, and while they were efficient, they didn’t make many havoc plays with their front seven.

Coordinator Clancy Pendergast shored up those weaknesses reasonably. USC improved from 107th to 75th in IsoPPP, from 88th to 33rd in points allowed per scoring opportunity, and from 73rd to 32nd in front-seven havoc rate. Success!

They also plummeted from 19th to 91st in rushing success rate and grew even less disruptive against the run, falling from 80th to 113th in stuff rate (run stops at or behind the line). They had a fantastic pass defense, and their pass rush improved dramatically, but it didn’t matter because opponents didn’t really have to pass.

Due to multiple injuries, USC got only four games out of star outside linebacker Porter Gustin, who had led the team with 7.5 non-sack tackles for loss in 2016. [Gustin might miss the start of 2018 with a torn meniscus, but he’s expected back early in the season. The text of this preview has been updated to reflect his status.]

While fellow OLB Uchenna Nwosu emerged as a major weapon in pass defense (9.5 sacks, plus 14 passes defensed, the most in the country for a non-DB), he wasn’t as disruptive against the run (two non-sack TFLs). The same went for end Rasheem Green (10 sacks, 2.5 non-sack TFLs) and tackle Josh Fatu (six and two, respectively).

Perhaps Gustin’s return can restore a bit of run-pass balance. It’s going to be harder to rush the passer without Nwosu, Green, and Fatu, but Gustin and end Christian Rector (7.5 sacks, 3.5 non-sack TFLs) are still there, and they might be able to lend some help to ILB Cameron Smith, the only Trojan to take part in more than eight run stuffs last year.

The line is a bit unproven after Rector and senior end Malik Dorton; sophomores Brandon Pili and Liam Jimmons saw some rotation time, but Pendergast will likely be leaning on a pair of blue-chip redshirt freshmen — end Jay Tufele and tackle Marlon Tuipulotu — to help with both depth and a little bit of play-making.

The linebacking corps — stocked with Smith, Gustin, juniors John Houston Jr. and Jordan Iosefa, and perhaps incoming freshman blue-chipper Palaie Gaoteote IV — should thrive.

Even if the pass rush regresses a bit, the secondary should be fine. The Trojans must replace safety Chris Hawkins (6.5 TFLs, three passes defensed) and corner Jack Jones (11 passes defensed), who left for junior college. But they’re stocked at safety, where Marvell Tell III and nickel back Ajene Harris (combined: four TFLs and 14 passes defensed) are back, as are former star recruits like junior Ykili Ross, sophomore Bubba Bolden, and redshirt freshman Isaiah Pola-Mao. And they still have Iman Marshall as an anchor at corner.

Either redshirt freshman Greg Johnson (you guessed it, a former blue-chipper) or one of two seniors (Isaiah Langley or Jonathan Lockett) will need to step up in Jones’ absence, but odds are in USC’s favor. If the run defense is good, the pass defense should again be awesome.

Special Teams

USC got worse in every special teams efficiency category and fell from 19th to 89th in Special Teams S&P+, but at least there was youth to blame. Kicker Chase McGrath was a freshman, as was a pretty strong return man in Velus Jones Jr.

Everybody’s back, from McGrath and Jones to senior punter Reid Budrovich and punt returner Ajene Harris, and McGrath wasn’t that far from being a nice place-kicking weapon. I’m guessing there’s a rebound here, if only into the top-60 range.

2018 outlook

It’s so hard to project teams that have most of what they need, but have a massive question mark at quarterback. USC won’t need a 2016-Darnold performance to be a clear Pac-12 South favorite, but the Trojans still need competence.

They’ll need fast competence, too. Per S&P+, USC is 15th overall and a projected favorite in 10 of 12 games, but the Trojans play at Stanford in week two and at Texas in week three, then return home for a short-week game against Washington State and a visit to Arizona.

USC hasn’t been a fast starter under Helton, and if it takes until October to get rolling, the Trojans could be 2-3 and hoping to salvage a nine-win season. But if Sears/Daniels/Fink finds a nice rhythm, every game on the schedule is winnable.

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