THE ANNOUNCEMENTS CAME 37 hours apart in November 2021, two coaching hires -- and abrupt departures -- that rocked college football and would forever bind USC's Lincoln Riley and LSU's Brian Kelly.

Riley and Kelly left two programs that nobody leaves, Oklahoma and Notre Dame, respectively, for the chance to pursue national championships with the Trojans and Tigers. They haven't had much of a chance to reflect on their moves, at least with one another, although the time will eventually come.

"We get like 20 seconds to talk to each other as we're passing through hallways," Kelly told ESPN. "But certainly if we did have a chance, it would probably be the first thing that we would talk about, and laugh about it now. We wouldn't have laughed about it then."

The midfield logo at Allegiant Stadium on Sunday in Las Vegas might be the perfect place for Kelly and Riley to recount how they reached their current jobs, what has happened since their historic moves and what comes next. Kelly and Riley will share a field as No. 13 LSU and No. 23 USC begin the season in the Modelo Vegas Kickoff Classic (7:30 ET, ABC).

The way both coaches came into their roles is among a supersized set of similarities between USC and LSU as Year 3 begins for Riley and Kelly. Both have had moderate success, including division titles in their first seasons, but are still searching for their first College Football Playoff appearances with USC and LSU.

"There's a lot of parallels between the two groups," Riley told ESPN at Big Ten media days. "There is a lot to it."

Both have mentored the past two Heisman Trophy winners in USC's Caleb Williams (2022) and LSU's Jayden Daniels, who became the first two picks in April's NFL draft. Riley and Kelly will turn to quarterback replacements -- Miller Moss and Garrett Nussmeier -- who went against the transfer trend, remained at their schools, delivered big bowl performances and will finally get their opportunities to start.

The resemblances exist perhaps even more so with defenses that have fallen apart and needed expensive rehabs. LSU hired Missouri defensive coordinator Blake Baker to oversee its unit, and made him the nation's highest-paid assistant at $2.5 million annually, while filling out the staff with notable position coaches. USC went across town and plucked D'Anton Lynn from rival UCLA, paying more than $2 million annually for the 34-year-old, a source told ESPN, to lead a staff with vast and diverse experience.

"That's where you may drill down on the real similarities, the investment in the coaching personnel," Kelly said. "This is a huge investment. USC has hired some of the best coaches in the country on defense, and it comes at a premium, and we've done the same here at LSU. You're trying to attract the best in the marketplace. So both have gone all in.

"We've pushed all of our chips into the middle, literally and figuratively."

Both are in different stages of roster construction and recruiting, and have taken different approaches toward name, image and likeness.

LSU and USC have more commonalities than contrasts, though, as they kick off Year 3 under two glitzy coaches under the bright lights of Las Vegas. The teams' biggest bond remains a shared pursuit of national championships, but how far is each away from the sport's pinnacle?

KELLY HAS A theory about resetting on defense versus offense. An offensive reboot, he said, is typically done for schematic reasons. When a team overhauls its defensive approach, like LSU and USC did this winter, there are other problems at play.

Last fall, LSU experienced what Kelly saw as "a lack of connection" to what was being taught. Kelly didn't have a problem with the defensive scheme but saw players lacking energy and resolve at times. The Tigers finished 115th nationally against the pass and 106th in efficiency. They allowed an average of 47.3 points in their three losses.

Riley defended USC's approach on defense -- and the man calling plays, coordinator Alex Grinch, who made the move with him from Oklahoma -- until he couldn't any longer, making a change in early November. In Riley's first two seasons, USC ranked 115th nationally in points allowed, 124th in average yards per play allowed and 129th in percentage of opponent drives resulting in touchdowns. The Trojans were prone to breakdowns, which became more glaring in 2023 after being somewhat masked by creating turnovers in 2022.

Sweeping changes were needed and both schools took big swings with their defensive staffs. No two schools who retained their head coaches poured more money into their defensive coaching than LSU and USC did this offseason. Baker and Lynn are the headliners, but there's star power behind them.

LSU plucked Bo Davis, a former Tigers defensive lineman and assistant, and one of the most accomplished defensive line coaches in recent SEC history, from Texas. Kevin Peoples and Jake Olsen, who worked with Baker at Missouri, also made the move, while Corey Raymond, another former LSU player who produced 14 NFL draft picks as the school's secondary coach from 2012 to 2021, returned to the same role.

USC brought in Matt Entz, a two-time FCS national championship-winning coach at North Dakota State, as well as NFL assistant Eric Henderson, Houston defensive coordinator Doug Belk and others to work under Lynn.

Lynn has emphasized getting bigger up front, part of a teamwide initiative that added more than 1,400 pounds during the offseason. USC also made several key transfer additions, including linebacker Easton Mascarenas-Arnold and safety Akili Arnold from Oregon State and safety Kamari Ramsey from UCLA.

"You've got to get off to a good start, just get some confidence," Riley said. "At places like this and like [LSU], once you get some momentum going, then it'll take hold. All of a sudden, we'll recruit a little bit better and it just builds and builds and builds. It takes that spark to get it going, and obviously, we both made some big changes in search of that. Both get their first chance on that type of stage, to see what we've got."

Both defenses will be tested right away. Although LSU loses Daniels and two other first-round draft picks, wide receivers Malik Nabers and Brian Thomas Jr., from the nation's No. 1 offense, it still returns a promising quarterback in Nussmeier and an offensive line that could be the best in the FBS.

LSU offensive tackles Will Campbell and Emery Jones Jr. are both projected as first-round draft picks in 2025.

"You talk to a lot of people, and before I even turned on the tape, a lot of people said those are two of the best tackles in the country," Lynn told ESPN. "It's really exciting to have a challenge like that Week 1."

USC led the nation in touchdowns (150) and points per game (41.6) during Riley's two seasons. Although the offense loses Williams and four other draft picks, including running back MarShawn Lloyd (third round), the Trojans bring back dynamic sophomore Zachariah Branch and other big-play threats for Moss.

"Staying connected, staying together, is something that we've really looked into, especially when things aren't going well," LSU linebacker Greg Penn III said. "Guys will be flying around, more effort, guys are hungry. This whole camp, we've gone after it. We've gotten better each day. So just coming together and going out there and playing against a great opponent like USC, we can really see what we are as a defense."

OF THE PAST seven Heisman Trophy winners, five either played quarterback for Riley (Baker Mayfield and Kyler Murray at Oklahoma and Williams) or for LSU (Joe Burrow, Daniels). Riley is regarded as the nation's top quarterback developer. LSU, despite its roots as DBU, has pivoted to become an offense-centric program, thanks in part to Burrow, Daniels and a group that ranks No. 5 nationally in scoring and No. 3 in total QBR since 2019.

The two quarterbacks who take the field Sunday have taken different paths than the recent Riley or LSU signal-callers but remarkably similar ones to each other. Both Moss and Nussmeier were top-65 recruits in the 2021 class -- ESPN ranked Moss at 39 and Nussmeier at 63. Both committed to play for coaches (USC's Clay Helton, LSU's Ed Orgeron) who are no longer at the schools, but both remained through leadership change.

Nussmeier and Moss also spent three seasons down the depth chart as LSU and USC brought in transfers (Daniels and Williams) to lead their offenses.

"Clearly, patience is not a virtue any more. It's something that we don't see," Kelly said. "And clearly, both of these young men have been patient, have waited for their opportunity, and are going to get rewarded.

"How cool is that?"

Moss and Nussmeier both earned their first career starts in last year's bowl games, as Williams and Daniels opted out to prepare for the draft. Facing ACC runner-up Louisville in the Holiday Bowl, Moss threw six touchdown passes, a Holiday Bowl record and a USC bowl record, and 372 yards en route to MVP honors.

Five days later, Nussmeier rallied LSU past Wisconsin in the ReliaQuest Bowl, setting career highs for completions (31), passing yards (395) and passing touchdowns (3) while earning MVP honors. The son of longtime NFL and college coach Doug Nussmeier also showed his big-game poise against eventual national champion Georgia in the 2022 SEC championship, when he had 294 yards passing and two touchdowns in the second half of a 50-30 loss.

"He's best when the lights are on, and the lights are gonna be on in Vegas," said Penn, who came into LSU with Nussmeier in 2021. "With the transfer portal, usually guys just leave. That just speaks to his character and him wanting to be the quarterback for the LSU Tigers. He's waited his turn, and I think he'll have a great outcome."

Moss needed only two years to graduate from USC with a pre-law degree, twice making the Pac-12 academic honor roll. He is now pursuing a master's in social entrepreneurship and this summer said that he would probably be in the middle of recruiting for investment banking jobs, if he didn't have a team to lead.

"The opportunity to play for Coach Riley is obviously attractive as a quarterback," Moss said. "Also, the guy I was sitting behind was pretty good, so that gave me a little solace in doing so. It was extremely frustrating not playing, I'd be lying if I said that wasn't the case. But I tried to have some foresight in doing so, and hopefully it's going to continue to pay off."

KELLY AND RILEY know each other casually, but they aren't very close.

They are separated in age -- Kelly is 62, Riley turns 41 on Thursday -- and have different backgrounds. Riley grew up near the Texas-New Mexico border in Muleshoe, Texas, and came up through the famed Mike Leach Air Raid coaching tree at Texas Tech. Kelly is from outside of Boston and spent the first 20 years of his career in college football's lower divisions. They shared an agent, Trace Armstrong, and Riley once interviewed with Kelly for a job as a young assistant at East Carolina.

But the coaches' most notable connection might always be those frenetic hours after the 2021 regular season, when they left two of the top six winningest programs in the sport.

"I saw him at the [NFL] draft; we caught up for just a second," Riley said. "At some point, though, we will have a good laugh about it."

Kelly looks forward to that conversation.

"It was pretty tense and difficult, timing-wise, for both of us," he said. "It's one of those situations where we'll both probably have a different perspective on it, but one that each one of us would appreciate."

Although Riley and Kelly made their moves almost in lockstep, they took over programs in different conditions. USC went 4-8 in 2021 and was 22-21 in the four years before Riley's arrival. In the previous 13 seasons, the Trojans had just two AP top-10 finishes and finished unranked six times, while never making the CFP.

LSU, meanwhile, was just two years removed from the national championship when it hired Kelly. Although the Tigers had slipped on the field toward the end of Orgeron's tenure, they still had seven players drafted in 2021 and 10 in 2022.

"SC won four games before we got there, [Kelly] didn't quite take that over," Riley said. "I'm sure they had some work to do and I'm not an expert in what he was taking over, but that one was a little more established and down the line than what we grabbed onto."

At Big Ten media day, Riley detailed the key areas where USC had fallen behind. Twenty years removed from a national championship, USC is still working to match its peer programs. Even the transfer portal, where USC has had some notable successes including Williams, is an area Riley would like to de-emphasize in the coming years.

"We are playing catch-up," Riley said. "We're playing catch-up in facilities, we're playing catch-up in NIL, we've been playing catch-up in resources within the program, we've been playing catch-up in damn near every way you can think of. But when we catch up, and we are going to catch up, that's when the things that this place has that others don't [will] show up again. It's coming."

USC will play one of the nation's toughest schedules this fall, bookended by LSU and No. 7 Notre Dame and also featuring matchups against No. 8 Penn State (home), No. 9 Michigan (road) and others in its new league. The Trojans enter the season with a win total of 7.5, according to ESPN BET, which could leave them well outside the CFP conversation.

Riley never lost more than two games during a remarkable five-year run at Oklahoma, but he had eight losses in his first two years at USC. How he navigates Year 3 will shape how many view the program's trajectory. A win over LSU could signal a positive shift.

"It does kind of create a unique atmosphere for a great matchup," Moss said. "It's an important game for both programs, and I think we're really excited as a team to go take advantage of that."

The past three LSU coaches won national championships, all within their first four seasons at the school. Kelly's teams have provided some fireworks, especially on offense, but also dropped their two openers to Florida State and couldn't overcome several dud performances on defense.

LSU enters the season with a win total of 9.5 and decent CFP odds, but USC will provide a good test as the Tigers try to recapture their balance.

"It gives you a good indication of where your strengths and weaknesses are, when you play a team like this coming out of the gates," Kelly said. "So there is a lot that will be uncovered. You just would rather not be behind, coming out of the first game, where you put yourself in a very difficult spot.

"Clearly, momentum is a big thing in the opener."