Although there was still a lot to love about Oklahoma entering this season, Lincoln Riley stepped into a tricky situation.

Oklahoma lost a Heisman Trophy finalist in wideout Dede Westbrook and a pair of NFL running backs in Samaje Perine and Joe Mixon from last year's Big 12 championship team, which finished 11-2 and won the Sugar Bowl. The players weren't even the biggest losses, though: In June, head coach Bob Stoops abruptly retired after 18 years, 10 Big 12 titles and one national title. Riley is the 34-year-old first-time head coach charged with replacing a legend in a season with high expectations and little time to prepare for an enormous job upon being promoted from offensive coordinator.

And yet: Oklahoma is even better than it was last year, with one of the greatest offenses in the history of a school that has had several all-time great offenses.

The combination of Riley's play-calling and Baker Mayfield's emergence in 2015 and '16 revitalized Oklahoma with back-to-back top-five seasons after an 8-5 record and stagnation on offense in 2014. Stoops subsequently passed the keys to one of the sport's most prestigious jobs in the middle of the offseason, and Riley and Mayfield have built on their previous success to deliver what could turn out to be one of the most successful debut seasons for any coach in college football history.

Despite a midseason home loss to Iowa State, Oklahoma has a 12-1 record, won a third straight Big 12 championship and will make its second College Football Playoff appearance in three years. Mayfield won the Heisman Trophy after back-to-back top four finishes, teaming with Riley, a veteran offensive line, tight end Mark Andrews and a group of rising skill players to lead the nation in yards per play at 8.4 -- by far the highest average of any power conference team since 2000, according to Sports-Reference.

Oklahoma won at Ohio State by 15, won rivalry games against Texas and Oklahoma State and swept TCU in two games to win the Big 12. Riley has coached a Heisman winner and a historically great offense to a playoff bid, and there's still an opportunity for more: If Oklahoma beats Georgia in Monday's Rose Bowl, it will get to play either Alabama or Clemson for the national title. Thus, Riley can join Larry Coker, Dennis Erickson and Bennie Oosterbaan in the exclusive club of coaches who won a national championship in their first season as head coach at that school.

Riley has already had one of the most impressive debuts ever. While he inherited an excellent situation from Stoops, he's part of the reason why it was such a good situation in the first place. He's already knocking on the door of the best first seasons in college football history, with a chance to climb toward the top of the following list.

This list -- with the help of Sports-Reference -- includes coaches who finished their debut seasons ranked in the top four of the AP poll (thus, it excludes spectacular first years from coaches like Chris Petersen at Boise State in 2006 and Kevin Sumlin at Texas A&M in 2012, as they finished fifth). Oklahoma is currently No. 2 in both the playoff and AP rankings, and this is the company Riley is chasing in the playoff:

20. Tommy Prothro, UCLA, 1965. After a successful stint at Oregon State, Prothro jumped to UCLA, which was coming off three straight losing seasons. Prothro quickly jumpstarted the Bruins. Although they lost twice to Michigan State and Tennessee and tied Missouri, they beat USC and stunned No. 1 Michigan State, 14-12, in the Rose Bowl to finish No. 4 in the AP poll.

19. Terry Brennan, Notre Dame, 1954. Frank Leahy went 9-0-1 in his final season in 1953, setting the stage for a strong debut from Brennan, a former player the previous decade. Brennan lost his second game to Purdue but otherwise had a big season, capped by wins over USC and SMU to finish 9-1 with a No. 4 ranking. It proved to be the best of his five seasons on the job.

18. Bill Battle, Tennessee, 1970. Doug Dickey left Tennessee for Florida, his alma mater, after the 1969 season. Tennessee promoted Battle -- an Alabama alum who was the Tide's athletic director the past few years -- and he started strong, going 11-1 with a shutout win over Alabama. The Vols' only loss came in their second game against Auburn. They beat Air Force in the Sugar Bowl and finished No. 4.

17. Fred Akers, Texas, 1977. Akers had been an assistant under Darrell Royal, left for two years to coach Wyoming and then was brought back to fill Royal's enormous shoes. Akers had mixed results in his career, but after Texas went 5-5-1 in Royal's finale, Akers led the Longhorns to an 11-1 campaign in 1977, with a perfect national championship season spoiled thanks to a blowout loss to Notre Dame in the Cotton Bowl.

16. Lou Holtz, Arkansas, 1977. After just one year in the NFL with the Jets, Holtz returned to the college ranks and immediately had success at Arkansas upon replacing the legendary Frank Broyles. The Razorbacks went 5-5-1 in Broyles' final season, and then Holtz went 11-1, losing only to No. 2 Texas and ultimately beating No. 2 Oklahoma 31-6 in the Orange Bowl to finish No. 3. Holtz stayed at Arkansas for seven seasons and eventually won a national title at Notre Dame.

15. Frank Leahy, Notre Dame, 1941. Leahy actually had two first seasons. In 1946, he returned from a two-year World War II hiatus and led Notre Dame to the national title. But in his actual Notre Dame debut in 1941, after leading Boston College to an unbeaten season, Leahy went 8-0-1, with a 0-0 tie to Army but an otherwise unblemished season. Notre Dame finished No. 3, and Leahy brought four national titles to South Bend by the end of the decade.

14. Terry Bowden, Auburn, 1993. Auburn was hit with NCAA sanctions at the end of the Pat Dye era, so Bowden was unable to participate in the postseason in his debut as head coach upon leaving Samford. Bowden nevertheless led the Tigers to a perfect but unrecognized season, as they beat No. 4 Florida and No. 11 Alabama on the way to going 11-0 with a No. 4 final ranking.

13. Urban Meyer, Ohio State, 2012. After a one-year hiatus from coaching, Meyer led Ohio State to a perfect 12-0 season, but the Buckeyes were banned from playing in a bowl game because of the NCAA scandal that cost Jim Tressel his job. Against a relatively weak schedule, the Buckeyes finished No. 3. Alabama beat Notre Dame for the national title, while Ohio State stayed home.

12. Chuck Fairbanks, Oklahoma, 1967. The Sooners hit a downturn in three seasons after Bud Wilkinson stepped down, but Fairbanks quickly revived the program. He went 10-1 in 1967 with a No. 3 finish and a dramatic Orange Bowl win over Tennessee. The only problem? The Sooners lost to Texas, 9-7. Fairbanks went 52-15-1 in six seasons before leaving for the New England Patriots.

11. Barry Switzer, Oklahoma, 1973. Switzer served as Fairbanks' offensive coordinator and was promoted to head coach in 1973. The team was banned from the postseason by the NCAA for two years, but Switzer's first team went 10-0-1 and finished No. 3, the only blemish being a tie with then-No. 1 USC. Switzer and his wishbone offense went on to win three national titles.

10. John Robinson, USC, 1976. John McKay won his final national titles in 1972 and 1974, and he leaped to the NFL's Tampa Bay Buccaneers after an 8-4 campaign in 1975. 11-1, No. 2, Rose Bowl win. Robinson had been offensive coordinator for those two championships, and after a year on the staff of the Oakland Raiders, Robinson returned to USC as head coach. Robison was blown out by Missouri in his debut, then rebounded to rattle off 11 wins in a row, finishing No. 2 after a 14-6 Rose Bowl win over Michigan. He won a share of the national title two years later.

9. Earle Bruce, Ohio State, 1979. A former Ohio State player and assistant, Bruce left Iowa State to replace Woody Hayes and had his best season in his debut. The Buckeyes would go on to lose at least three games in his next eight campaigns, but Bruce started off by going 11-1 in 1979. Unfortunately, the last loss came in heartbreaking fashion at the worst moment: The Buckeyes fell, 17-16, in the Rose Bowl against USC, costing them the national championship.

8. Bobby Collins, SMU, 1981. When Ron Meyer left SMU to coach the New England Patriots, Collins jumped from Southern Miss to SMU and became part of an impending firestorm. Things started out well on the field: Collins inherited a 10-1 team that returned Eric Dickerson and Craig James. Led by that backfield, the Mustangs went 11-0-1, won the Cotton Bowl and finished second in the polls behind Penn State. It's the best season in SMU history, according to the polls, but Collins resigned after the 1986 season and the Mustangs were hit with the NCAA's death penalty.

7. Gus Malzahn, Auburn, 2013. Malzahn served as offensive coordinator for Auburn's national championship season in 2010, when Cam Newton won the Heisman. Gene Chizik was fired after a downfall to 3-9 in 2012, and Auburn brought back Malzahn, who spent the '12 season as head coach at Arkansas State. Auburn lost the national title in dramatic fashion to Florida State, but it had one of the most memorable seasons ever, improving by nine wins with the help of the Prayer at Jordan-Hare against Georgia and the Kick Six against Alabama. The Tigers finished 12-2 and ranked No. 2.

6. Carroll Widdoes, Ohio State, 1944. Widdoes spent only two seasons as head coach, replacing Paul Brown in 1944 when Brown became a lieutenant in the U.S. Navy. Widdoes and Ohio State beat Brown's Great Lakes Navy team and proceeded to finish 9-0 and ranked No. 3, with Les Horvath winning Ohio State's first Heisman Trophy. Widdoes coached one more 7-2 season in Columbus and later became head coach at Ohio.

5. Ara Parseghian, Notre Dame, 1964. Notre Dame football fell on hard times in the early 1960s, but Parseghian quickly fixed things upon arriving from Northwestern. He went 9-1 in his debut, with a 20-17 loss at USC in the regular-season finale costing the Fighting Irish the AP national title. The Irish finished third in the AP poll, but they were still crowned national champions by the National Football Foundation, in a three-way split with Alabama and Arkansas. Notre Dame, however, does not officially claim a share of the 1964 national title. Parseghian went on to win two titles and coach nine top-10 teams in 11 seasons.

4. Clark Shaughnessy, Stanford, 1940. When Chicago abolished football after the 1939 season, Shaughnessy headed west to continue coaching. He introduced the T-formation at Stanford and promptly went 10-0 in his debut with a team that had gone 1-7-1 the year before. Stanford ended the season by beating Nebraska in the Rose Bowl, but despite its perfect record, it finished No. 2 in the AP poll behind national champion Minnesota. Shaughnessy spent only one more 6-3 season at Stanford before moving to Maryland as World War II altered the college football landscape. (Stanford didn't play football from 1943-45.)

3. Dennis Erickson, Miami, 1989. Miami made a habit of coaches leaving behind powerhouses upon jumping to the pros. Jimmy Johnson coached three straight top-two teams from 1986-88 before leaving for the Dallas Cowboys. Erickson had seven years of head coaching experience at three schools -- Idaho, Wyoming, Washington State -- when he was hired to replace Johnson. His debut featured a 24-10 loss to Florida State, but Miami climbed back to No. 2, beat Alabama in the Sugar Bowl and vaulted to No. 1 for the national title thanks to Colorado's Orange Bowl loss to Notre Dame. Erickson won another title in 1991 and left for the NFL in 1995.

2. Bennie Oosterbaan, Michigan, 1948. In 1947, Fritz Crisler went out with a bang, going 10-0 and winning the Rose Bowl with a team that innovated with offensive and defensive platoons. Oosterbaan, a legendary Wolverines player, had served on the coaching staff since his playing career ended two decades earlier. He was a natural choice to replace Crisler, and he led Michigan to its second straight undefeated season. The Wolverines captured the national championship at 9-0, beating Ohio State 13-3 in their season finale. Oosterbaan coached three more AP top-10 teams in 11 seasons as head coach.

1. Larry Coker, Miami, 2001. When Butch Davis decided to leave Miami for the Cleveland Browns, he left behind one of the greatest rosters in college football history. Miami opted for continuity, allowing Coker to step up from offensive coordinator to head coach for a team that went 11-1 and finished No. 2 in the AP poll in 2000. Among the returnees: Ken Dorsey, Clinton Portis, Willis McGahee, Frank Gore, Andre Johnson, Jeremy Shockey, Najeh Davenport, Bryant McKinnie, Ed Reed, Jonathan Vilma, Phillip Buchanon, Vince Wilfork, Antrel Rolle and more. Miami dominated nearly everybody in its path, holding eight opponents to seven points or less in a 12-0 season. Coker led Miami to its most recent national champion, as the Hurricanes throttled Nebraska in the Rose Bowl for the BCS title. Coker presided over a successful transition, but nobody has ever inherited a more talented roster. The Hurricanes subsequently dropped in the rankings each of his six seasons before he was let go after a 7-6 campaign in 2006.

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