One semifinal features teams with so much familiarity that their upcoming meeting in New Orleans will put a bow on "The Trilogy."

The other semifinal includes participants in Oklahoma and Georgia that have matched up before. The Sooners and Bulldogs will meet on a stage, the Rose Bowl Game presented by Northwestern Mutual, that each has visited only once -- Oklahoma in 2003 and Georgia six decades earlier in 1943.

Oklahoma's machinelike offense, with Heisman Trophy winner Baker Mayfield at the controls, goes up against a fast and ferocious Georgia defense led by Butkus Award winner Roquan Smith at linebacker. If you like contrasting styles and a healthy dose of unpredictability, the Rose Bowl should be your preferred College Football Playoff semifinal.

Coaches who faced or scouted the teams say Oklahoma hasn't encountered a challenge quite like Georgia, and vice versa. Here's a closer look at the Rose Bowl through the eyes of coaches around the country.

Roquan Smith (3) leads Georgia's talented linebackers. Brett Davis-USA TODAY Sports

There's no disguising the main event in California: Mayfield and the nation's No. 1 offense (583.3 yards per game) lining up across from a Georgia defense that ranks in the top five nationally in points allowed per game (13.2), yards allowed per game (270.9), pass yards allowed per game (158.3) and adjusted QBR (21.4).

It's what fans want to see. It's what coaches want to see.

"Georgia has got all those athletes, but Oklahoma is really, really good on offense," a Big 12 assistant said. "It will be interesting."

Some are quick to label Oklahoma as another Big 12-inflated offense that will surely struggle against Georgia's elite defenders and schemes. Just two years ago, Mayfield led a high-powered Oklahoma offense into the semifinal against Clemson, and the Sooners were held well below their averages (17 points, 378 yards) in a loss.

But coaches say this Oklahoma offense exceeds its league or its competition, which includes an Ohio State team filled with future pros that the Sooners scored 28 second-half points against (Mayfield passed for 386 yards and three touchdowns).

"They're playing a different game," an SEC defensive coordinator said. "They have good players, but people do not have numbers on them in the run game, and they don't have leverages on them. As far as schematic stuff, Oklahoma's the best I've seen. The counter stuff they're doing and the reading, they're way out-leveraging and outnumbering people."

Oklahoma averages a nation-leading 8.44 yards per play, nearly a full yard more than the No. 2 team (UCF at 7.6 YPP). Georgia faced four teams that ranked in the top 30 in yards per play, but coaches felt Missouri -- top 10 in scoring, yards per game, yards per play and sacks allowed -- is the most comparable opponent to what the Bulldogs will see New Year's Day.

Missouri scored 28 points against Georgia, the second-highest total the Bulldogs gave up all season, but had two touchdowns on 63-yard passes and a third on a 5-yard drive after a Jake Fromm interception. Georgia allowed only 10 first downs and 59 rush yards to the Tigers.

"Georgia's linebackers are freaky," an SEC offensive line coach said. "They fly around, and they're physical at the point of attack."

Another offensive assistant added of Georgia's scheme: "They try to let 3 [Smith] run. It'll be a challenge for Oklahoma."

One coach who has scouted Baker Mayfield compares him to Seattle QB Russell Wilson. Brett Deering/Getty Images

The approach pays off as Smith's speed constantly puts him around the ball. A unanimous All-America selection, Smith is Georgia's leading tackler (113) for the second consecutive season. He also leads the Bulldogs in quarterback hurries (17) and sacks (5.5), and ranks second in tackles for loss (10.5). Along with Lorenzo Carter, Davin Bellamy and D'Andre Walker, Smith leads one of the most dynamic position groups in all of college football.

Although coaches echo the praise of Georgia's linebackers, they're somewhat split on the Bulldogs' defensive line, which doesn't get as much acclaim. One SEC offensive assistant said, "They aren't bad players, but I don't think they're world-beaters by any means." An offensive line coach who faced Georgia praised the way the linemen shed blocks.

"They do a hell of a job," he said, "Big dudes, athletic."

How Georgia's defensive front handles Oklahoma's offensive line will be very telling. Led by Outland Trophy finalist Orlando Brown at left tackle, the Sooners boast arguably the nation's best line. Despite losing two backs to the NFL, OU averages 5.6 yards per rush (13th nationally) with 88 runs of 10 yards or longer (18th nationally). Brown, described by one opposing coach as "a massive human being," faced many of Georgia's stars while playing high school ball in the state.

Though Brown gets most of the attention, an SEC coach mentioned right tackle Bobby Evans as another standout. The Sooners' line enters the Rose Bowl with 141 combined career starts.

"I haven't seen very many offensive lines that look like Oklahoma's in the 20 years that I've been coaching," a Big 12 assistant said.

Don't expect Georgia to be intimidated. The linebackers simply ran around Notre Dame's decorated line in a 20-19 win. Their speed also gave Auburn trouble in the SEC championship. Notre Dame won the Joe Moore Award as the nation's top offensive line, and Auburn was a finalist (Oklahoma inexplicably didn't make the top three).

Mayfield's elusiveness can frustrate even the most gifted defenders, but coaches say he's going to have to be smarter with his footwork against a team like Georgia. One coach who has scouted Mayfield noted a similarity to Russell Wilson -- neither quarterback rushes for many yards but both create opportunities for big pass plays by running to a spot and then attacking downfield.

"He scrambles to throw," one coach said of Mayfield, who has 310 yards on 85 rushes this season. "He doesn't scramble to run. The defense has to lock in and stay in their rush lanes and stay in coverage, instead of coming up.

"You do your job, you'll be good. If not, there's a reason he won the Heisman."

Georgia might not have faced an exact replica of Oklahoma's offense this season, but it saw bits and pieces: from Notre Dame's and Auburn's lines to Missouri's receiving corps to tight ends such as South Carolina's Hayden Hurst, a semifinalist for the Mackey Award won by Oklahoma's Mark Andrews (58 receptions, 906 yards, 8 touchdowns). Oklahoma, meanwhile, saw comparable athletes to Georgia at Ohio State, but the Big 12 had only two defenses (Texas and TCU) that rank in the top 40 nationally in ESPN's expected points added metric. The Sooners had their lowest points total of the season in a 29-24 win over Texas, and outscored TCU 79-37 in two victories.

Several coaches noted the tempo factor and wondered how fast Oklahoma's offense will operate in the game. The Sooners can go fast -- they averaged 78.7 plays during a three-game stretch -- but they rank only 73rd nationally in plays per game (69.1). Georgia doesn't use much tempo (64.2 plays per game) and faced several slow-operating offenses in the SEC East, so Oklahoma could force the Bulldogs to adjust.

"If Oklahoma's going to go really, really fast and spread them out, it's just not what you see in the SEC," an SEC offensive coach said. "They can take advantage of them."

There will be less attention on Georgia's offense and Oklahoma's defense, but the matchup is no less significant. Georgia's run-heavy scheme -- the Bulldogs run on more than 70 percent of their offensive plays -- has the potential to wear down Oklahoma, the only non-elite defense in the playoff. The Sooners held up pretty well against the run -- 144.2 yards per game allowed, 19 rushing touchdowns -- although teams such as Kansas State (6.4 YPC) and Oklahoma State (6.3 YPC) had success against them.

Georgia will attack with talented backs in Nick Chubb, Sony Michel and D'Andre Swift, who have combined for 2,720 yards and 29 touchdowns on 395 carries (6.9 YPC). The Bulldogs supplement the run with efficient passing from freshman Fromm, who threw 21 touchdowns and only five interceptions and completed more than 65 percent of his attempts in six games, including each of the past two.

"If they can block you and get the inside running game going, then you've probably got no chance because those backs are just that good," a Power 5 defensive coordinator said. "You've got to manage their rushing game and keep them under 200. If they can play-action pass you on first and second down, because their running game is so good, they're hard to defend. But they're just not real effective on third down because they don't protect the quarterback."

Fromm faces an Oklahoma defense that struggled early in Big 12 play but improved late, giving up 17.8 points and 321 yards in its past four games.

"They're not that strong," a Power 5 offensive coordinator said of the Sooners' D. "They're solid, but they're not great. They're not like Georgia's or Alabama's defense. Georgia's pretty salty, but is this quarterback [Fromm] really good enough to win the whole thing as a freshman? Baker can, but I don't know if [Oklahoma's] defense is good enough."

Whether it's Fromm or Oklahoma's defense or two young head coaches in Georgia's Kirby Smart and Oklahoma's Lincoln Riley, the Rose Bowl forecast is delightfully foggy. A Power 5 offensive coordinator best captured the potential polarity of the matchup when he predicted, "Either Georgia kills 'em or Baker Mayfield puts on a show."

Something in between would be ideal as the first ticket to the CFP national title game is punched in Pasadena.