How turnovers and timely defense explain USC’s odd season

There was a pass intercepted deep in USC territory, at the 25-yard line. There was another at USC’s 45. There were fumbles near midfield, at USC’s 29-yard line, at its own 23.

All of those plays shared two things in common: They all were potentially back-breaking turnovers that put the Trojans’ opponents in great position to score. And they all resulted in zero points, thanks to USC’s defense.

Coaches, players and fans have labored to make sense of a confounding first half of the season. USC is 5-1, a solid if slightly disappointing record through a difficult stretch. But the Trojans also have looked vulnerable, with thrilling wins or close escapes in four of five victories.

USC has committed 13 turnovers, which is among the most in the Football Bowl Subdivision. However, there’s another statistic that explains how the Trojans have lost only once: the number of points yielded following those turnovers.

Players and coaches didn’t know the number when asked this week.

“Um, I know they scored …” linebacker Cameron Smith said, pausing to think. “I don’t really know.”

Said safety Chris Hawkins: “It’s not a lot. Twenty?”

Try three — a single field goal.

“Three points?” Hawkins said. “I told you it wasn’t a lot!”

Analysis by SBNation and College Football Outsiders has found that a turnover costs a team about four to five points on average, including the points the offense misses out on because of the giveaway.

USC’s 13 turnovers could have been a crippling handicap. The defense’s proficiency following a turnover has limited the damage, potentially saving one or more wins this season.

Against Texas, an interception in the fourth quarter gave the Longhorns the ball at USC’s 25-yard line. Had Texas scored, there would have been no heroics from Trojans quarterback Sam Darnold at the end of regulation. Instead, USC took the ball right back with an interception.

“I say every week, if they don’t score we’ve got a good chance to win,” defensive coordinator Clancy Pendergast deadpanned.

Overall, USC’s defense is fairly average. The Trojans are 45th in the nation in scoring defense and 48th in yards per play allowed.

USC gives up points on almost one of every three non-turnover drives. After a turnover, USC has allowed a score on only one of 12 drives.

“That’s what we live for,” linebacker Uchenna Nwosu said.

The defense has also bailed out the offense by creating turnovers. USC ranks fifth nationally in turnovers forced, with 15. Late turnovers turned nervous games against Western Michigan and California into no-drama wins.

Against California, that required five turnovers.

“If we don’t get those turnovers, who knows?” Hawkins said. “I wish we could’ve got one in the Washington State game — we only got one. You get more turnovers, you win games.”

For the offense, the turnovers are a sign of a unit that has flirted with danger but skirted the most severe consequences. Over a season, USC might not remain so lucky after turnovers.

However, the offense might show rapid improvement — if USC does a better job of protecting the ball. The rest of the offensive metrics are similar to last season’s. USC’s yards per play is up. Third-down conversions are down, but only marginally. Red-zone scoring is about the same.

The big difference has been the giveaways.

Coach Clay Helton said he expected improvement in ball security.

Asked where USC might be had its defense not provided a bailout, he laughed and said, “I don’t want to think about it.”

Quick hits

Helton expects tight end Daniel Imatorbhebhe (hip flexor) to contribute “in some way” against Utah, but he might not play the entire game. ... Outside linebacker Porter Gustin (broken big toe, torn biceps) may return next week when USC plays Notre Dame. “If not, the following week,” Helton said.

zach.helfand@latimes.com

Follow Zach Helfand on Twitter @zhelfand