Given how the Trojans defense has performed this season, no one is treating it as the immovable object.
Then again, with the consistently inconsistent Kevin Riley under center for the Golden Bears, it might come down to which side can put it together for just one game (12:30 p.m. Saturday, Fox Sports Prime Ticket).
The numbers allowed by USC (4-2, 1-2 Pac-10) this season have been staggering, allowing 287 yards passing per game and 26 points per game. But it has been the inability to get off the field at the most critical moments that has been most troubling, notably in losses as time expired in each of the last two weeks.
As Cal coach Jeff Tedford said, "They're about five seconds from being 6-0 so they're still a great team."
Defensive backs coach Willie Mack Garza still can't explain those struggles.
"This is a unique situation for me," Garza said. "Most places that I've been we've been able to get off on third down and we've been very successful in this system on third down."
However, Riley might be the remedy. The senior quarterback attempted just 16 passes last week in a 35-7 win over UCLA, but even then Tedford was left answering questions about his erratic play.
Riley, who has the most wins of any active Pac-10 quarterback, has thrown for 931 yards and nine touchdowns against four interceptions this season, completing 60 percent of his passes.
Even with the punishing running of Shane Vereen powering Cal (3-2, 1-1 Pac-10), linebacker Chris Galippo spoke of the need to make Riley win the game.
"It's a lot harder to snap a ball, protect a quarterback, run a perfect route and throw a ball across the field than to just hand it off and run for six yards every play," said Galippo, who is expected to start at weakside linebacker in place of Malcolm Smith (knee). "If you can make them one dimensional and they have to throw the ball, you have an advantage."
The Trojans have actually fared far better against the run, allowing 141 yards per game, but Vereen has rushed for 577 yards and eight touchdowns.
"Riley can throw the ball, but this will be about running the ball for sure," USC coach Lane Kiffin said. "I would think he (Tedford) is going to come in and hand it off 50 times. We need to be ready."
Kiffin and Tedford are certainly familiar with each other. Kiffin was a quarterback-turned-graduate-assistant at Fresno State when Tedford was offensive coordinator for the Bulldogs.
"Yeah, I knew he was going to be a coach," Tedford said. "He spent long hours, even as a student he spent long hours in my office with me, at night, watching tape, and would always give suggestions and things like that. I've followed Lane for a long time. Lane's a friend and obviously one who I have a deeper relationship with because of him playing for me."
Much of Kiffin's offensive philosophies date back to his time playing under and working with Tedford.
"I definitely consider him a mentor," Kiffin said.
*Discuss more on the SCPlaybook.com message boards