Late last July, on the USC campus, offensive guard Jeff Byers took stock of the phenomenon of Pete Carroll.

“I think he stays around here because he has a blast,” Byers told me. “I think he loves Southern California. He’s got a great house. You go down to the beach and see him boogie-boarding.

“I don’t think he can get a better gig than this.”

Well, six months later, Pete Carroll obviously disagrees, leaving us to assess where the Pac-10 is without him.

How about: Rejoicing.

It’s hard to overstate the impact Carroll had on USC, and thus, on the Pac-10. He commanded the biggest dynasty in the history of football in this conference, and the iterations before it. It was bigger than Howard Jones or John McKay–two icons of the Trojans–bigger than Don James at Washington.

At the start of the 2007 season, I worked up a comparison of Carroll’s five-year run from 2002-2006 (59-6) that placed the Trojans sixth all-time in college football for that period, putting them in the discussion with outfits like Tom Osborne’s Nebraska teams of the mid-1990s (60-3), Bear Bryant’s Alabama of the early ’60s (50-5-1) and Barry Switzer’s Oklahoma of the early ’70s (54-3-1).

Before the comeuppance of 2009, Carroll stretched his seven-year record to 82-9, with two national titles.

It’s a risky assumption to believe somebody approximates that success, for a lot of reasons.

This isn’t following John Wooden at UCLA. But it isn’t succeeding Paul Hackett at USC, either, which is what Carroll did. The alumni there aren’t going to be happy with going 9-3.

For the new guy, it won’t be easy. Remember, as good as Carroll was, he struggled to regain the mountaintop in his final four seasons. Taylor Mays stayed the maximum and didn’t win a national title.

Not to say there aren’t a lot of ways to do it, but Carroll hit upon a formula–work hard, play hard–that succeeded famously. He combined charisma and competition. For kicks, he brought in people like comic Will Ferrell and singer Bill Withers and tightroped above the NCAA rule book.

His practices were as open as the pubs in Pioneer Square on a Seahawks Sunday. Will the next coach want to be so collegial, and if not, how does that play?

It would help to know: What is USC exactly? Is it the program that won or tied for seven straight Pac-10 championships under Carroll, or the one that fired four straight coaches immediately before him, seemingly unable to pinpoint the right fit?

No doubt the program is in far better shape than when Carroll got there. It has Heisman Trophies spilling off shelves at Heritage Hall, and USC will always have an appeal for Los Angeles recruits as the colossus in the inner city.

But here’s a number that tells you it’s about more than the talent in the LA area: Carson Palmer, the quarterback, was there five years, winning the Heisman his fifth season, which was Carroll’s second. Before that, the four USC teams in Palmer’s years were 25-24.

Post-Carroll, you’d think people like Rick Neuheisel at UCLA, Steve Sarkisian at Washington, Jeff Tedford at California and Chip Kelly at Oregon are panting at the idea of recruiting against USC, as in, “you did hear, Willie, that the Trojans aren’t out of the woods with the NCAA?”

Yeah, USC is still USC. But Pete Carroll cut a hell of a swath.