The Trojans have won double-digit games in consecutive years with head coach Clay Helton and QB Sam Darnold at the helm, but a season-ending three-score loss to a top-five team shows the gap this talented team still had to close to be among the nation's best.

ARLINGTON, Texas — When USC first visited AT&T Stadium for its 2016 season opener, Sam Darnold wasn’t the starting quarterback, it was Clay Helton’s first game as the permanent head coach and the Trojans faced the top team in the country in Alabama.

Nearly 16 months later, Friday night’s return to AT&T Stadium wasn’t nearly as demoralizing as the 52–6 pummeling handed down by the Crimson Tide. The 24–7 loss to Ohio State, however, does provide a wake-up call to the program.

J.T. Barrett’s 28-yard scamper to the end zone put the Buckeyes up 24–0 in the second quarter. The game was on the verge of a bloodbath, another embarrassing defeat to a marquee team on a major stage under Helton.

Unlike the Alabama humiliation, though, one unit showed up: USC’s defense. That side of the ball held Ohio State’s explosive offense in check throughout the game. One of the Buckeyes’ touchdowns came on a pick-six off Darnold, while another was a 19-yard scoring drive that was the result of a fumble recovery and ensuing return.

Yet USC’s offense, special teams and coaching failed to come close to reaching the level that the defense did, and all three are issues that have plagued the team the entire season. The Trojans were still able to prevail despite these mishaps against less-talented teams, but when they reared their ugly head against more even competition, it became clear that USC still has some work to do in catching up to college football’s elite.

It never added up for USC to have this much talent on offense and be this inconsistent. The Trojans would look unstoppable with the ball at times this season, then fall into a series of dry spells and turnovers.

Against the Buckeyes, the Trojans actually had more yards (413 to 277) and a higher yards per play (7.9 to 6.7). That translated into only seven points, which came on a 15-yard scoring drive gift-wrapped by an Ohio State muffed punt. On the surface, USC’s four turnovers were the killer in the offense’s inability to convert.

Darnold brought his season turnover total to 22—a number higher than 101 FBS teams’—with three more against Ohio State. His ball security is his most alarming trait as an NFL prospect. Going up against an Ohio State pass rush littered with future pros didn’t help on Friday night.

“I think sometimes over the course of a year, just trying to do too much honestly,” Darnold said after the game. “It sucks, but it’s true. I think it’s good that I’m aware of it, but just gotta be better. Can’t force a throw like I did on the pick-six, that was just really bad.

“Some of the strip sacks, those are going to happen when I’m going to throw and a guy comes from behind me and strips the ball out. But again, on some of the strip sacks, gotta keep two hands on the ball in the pocket. In terms of the turnovers all year, it sucks and it just kind of is what it is at this point.”

His performance against Ohio State, the closest thing to an NFL defense he saw all year, was a microcosm of his redshirt sophomore campaign, in which he alternated jaw-dropping plays with head-scratching throws in a display of maddening inconsistency. He threw a few beautiful deep balls along the sidelines, yet missed this easy touchdown toss to wideout Deontay Burnett. Those six points left off the board became zero after a missed field goal.

“I wouldn’t say we were off on some throws, I would just say that Ohio State had a great D-line,” Burnett said. “We were just a bit flustered. Timing was off a little bit, but I would just say we were a little flustered.”

But the issues on offense also run deeper. USC’s game plan wasn’t exactly a challenge for Ohio State to counter. The Buckeyes had the clear advantage with their defensive line and were consistently able to generate pressure and throttle USC’s entire offense. Offensive coordinator Tee Martin’s schemes were questioned earlier in the season by Darnold, and Friday night didn’t offer much evidence that the situation had improved since October.

USC didn’t challenge Ohio State by switching up the tempo or by calling creative plays that could dissuade the Buckeyes from blitzing over and over. Add in another disappointing special-teams performance this season—this time highlighted by short returns and a missed 28-yard field goal—and it’s clear that Helton has some major questions he has to answer this offseason regarding his staff. Are these assistant coaches ideal for maximizing the players’ talent and putting them in situations to succeed throughout the game? The answer for the majority of 2017 on offense and special teams has been no.

But there will also be questions surrounding Helton, unfair as they may be. USC has two double-digit win seasons and its first-ever Pac-12 title game victory with him at the helm. But despite its record, the 2017 team rarely impressed, playing to the level of lesser competition and failing to beat three of the four best teams on the schedule. USC has suffered its two biggest losses since 1990 under Helton as well, the 46-point drubbing to Alabama in ’16 and a 35-point embarrassment this season at the hands of Notre Dame.

Both of those huge defeats came when the opposition was ranked in the top-five, as Ohio State was entering Friday. USC did beat two high-level opponents last season in Washington and Penn State, but those potential tenure-defining victories for Helton late in the season failed to create momentum for this 2017 campaign filled with expectations.

USC didn’t come close to sniffing the College Football Playoff these past two years despite having arguably the most talented quarterback in school history and having several stars across other positions. Athletic director Lynn Swann needs to figure out if Helton is the right guy to lead the Trojans to the next level so they can closely compete against the elite programs like Alabama and Ohio State.

“We’ve had 11 wins,” Helton said. “We’ve won a Pac-12 championship. We’re proud of those accomplishments. But are we satisfied? No, we’re not. We won’t be satisfied until we win a national championship, and that will be our goal.

“Like I told our seniors in the locker room, they’ve laid the foundation for us to move forward. They moved us forward by winning a Pac-12 championship by having 11 wins. And they’ve laid the foundation for the next step, which is making it to the playoffs and winning a national championship.”

But that leap was supposed to be this season, when the foundation was laid following the Rose Bowl win over Penn State. Instead, if anything, it felt closer to not taking a step in any direction at all rather than forward.

The Cotton Bowl proved that USC still has a ways to go before reaching its goal. Sam Darnold, Clay Helton and Lynn Swann don’t have last season’s dream-like finish to fall back on when figuring out what the future holds.

So whether it’s judging readiness for the NFL, deciding if this is the right group of assistants to help develop the talent on the roster or figuring out if this head coach can lead USC to a championship, this Ohio State loss provides a wake-up call to the entire program.