The college football world changed dramatically when the Bowl Championship Series was formed 20 years ago, giving the sport a definitive championship game for the first time. To celebrate 20 years of championship games, ESPN Analytics calculated overall, offensive and defensive ratings to find the true strength of a champion through a comparison of top college football programs across seasons. The model includes a giant network of all FBS college football teams that played approximately 15,000 games over 20 years and assigns each team to a game, score and home-field advantage indicator within each season. The network establishes a team's strength interrelated with every other team in the network and returns a rating measured in points above the average team (zero rating).

With that in mind, let's get to the list.

Vince Young led Texas to the national championship but didn't win the Heisman Trophy in 2005. UT Athletics

1. 2005 Texas Longhorns

The 2005 Longhorns are the top championship team of the past 20 years in large part because they claim the best player of the past 20 years. Quarterback Vince Young, remarkably, didn't win the Heisman Trophy that season, but he produced one of the greatest individual seasons in recent college football history, culminating with one of the greatest individual game performances the sport has ever seen. In the 2006 Rose Bowl against heavily favored USC, Young completed 30 of 40 passes for 267 yards, rushed for 200 yards and delivered the game-winning play, an 8-yard touchdown dash on fourth down with 19 seconds remaining. That play defined the BCS era. And turned Young into a legend. Young wasn't the only star for Texas, which also boasted a top-10 defense. Michael Huff was the Jim Thorpe Award winner and, like Young, became a top-10 NFL draft pick. Linemen Jonathan Scott and Rodrique Wright were consensus All-Americans, as well. The '05 Longhorns never lost. And saved their best for the biggest stage. -- Jake Trotter

2. 2008 Florida Gators

Urban Meyer has called his 2008 Gators the best to ever play the game. Meyer obviously has a bias, but he also has a legitimate point. Nineteen players from that team were eventually drafted, and Tim Tebow ranks among the greatest quarterbacks in college football history. He helped lead the Gators' offense to 611 points, the highest scoring total in SEC history, all while playing against eight of the nation's top 30 defenses. But the offense went beyond him, with Percy Harvin, Chris Rainey, Jeff Demps, Louis Murphy, Aaron Hernandez and David Nelson making Florida virtually unstoppable. Defensively, Carlos Dunlap, Brandon Spikes and Joe Haden set the tone, giving Florida a nasty, aggressive edge. And then there's that "The Promise" speech Tebow made after an early season loss to Ole Miss, galvanizing the team to take its play to a championship level. Tebow took over late in the win over Oklahoma at the Orange Bowl, and the Gators' defense shut down the high-powered Sooners and Heisman winner Sam Bradford, holding them to 14 points and 363 total yards. -- Andrea Adelson

Miami's 2001 team that won the national title featured 38 future NFL draft picks, including Clinton Portis. Paul Chapman/USA TODAY Sports

3. 2001 Miami Hurricanes

You could make the argument this team belongs at No. 1 for a host of reasons, starting with the biggest: its sheer talent. The roster featured 38 future NFL draft picks, including 17 who went in the first round. Among the 22 starters in the 2002 Rose Bowl win over Nebraska to clinch the national title, 18 were drafted -- 11 in the first round. The offense started with quarterback Ken Dorsey but featured Clinton Portis, Andre Johnson and Jeremy Shockey creating weekly mismatches. Frank Gore and Willis McGahee were backups. The defense was even better, with Ed Reed, Jonathan Vilma, Jerome McDougle, Mike Rumph, D.J. Williams and Phillip Buchanon leading the way. Miami averaged 42.7 points and gave up an average of 9.8 points per game. If there's one knock, it's the schedule. Miami played in the Big East at the time, so its average opponent rank is not as good as '08 Florida or '05 Texas. The Hurricanes also had to survive scares late in the season against Boston College and Virginia Tech, and Nebraska was an inferior opponent in the championship game. That shouldn't detract from what this team accomplished. -- Adelson

4. 2013 Florida State Seminoles

The Seminoles would gladly take on 2001 Miami in a debate over the most talented team. Every starter on the 2013 Florida State squad, plus kicker Roberto Aguayo, landed on an NFL roster. Jameis Winston won the Heisman Trophy as a redshirt freshman, throwing for 3,820 yards and 38 touchdowns with Rashad Greene, Kelvin Benjamin, Devonta Freeman and Nick O'Leary among the skill position talent. Defensively, Lamarcus Joyner, Telvin Smith and Tim Jernigan set the tone with a tenaciousness Florida State is still trying to match. Florida State set an NCAA record for points scored in a season with 723, but what made this team so impressive beyond the talent was how easy it made everything look. The Seminoles won their first 13 games by an average of 42.3 points per game. Nobody came within single digits until Auburn in the BCS National Championship Game. Trailing in the fourth quarter for the first time all season, Winston threw the game-winning TD to Kelvin Benjamin with 13 seconds left to seal the undefeated season. -- Adelson

5. 2004 USC Trojans

The best team in conference history? It's certainly one of the primary teams in the discussion. Playing one of the toughest schedules in the country, the Trojans capped an undefeated season with the most lopsided championship game victory (55-19 against Oklahoma) in the BCS era. Even though QB Matt Leinart, RB Reggie Bush and RB LenDale White debuted with a national title the year before, it was during this year when they became household names. Leinart won the Heisman, White led the team in rushing, and Bush was the most exciting player in the country. Officially, USC was stripped of the title and forced to vacate its final two wins of the season because of Bush's extra-benefits scandal, but an asterisk doesn't have memory-erasing powers. This was an all-time great team and should be remembered as such -- over the next two NFL drafts, USC had 16 players get selected. -- Kyle Bonagura

Alabama avenged its only loss of the 2011 season in the BCS title game against LSU. AP Photo/Dave Martin

6. 2011 Alabama Crimson Tide

Alabama has had plenty of menacing defenses throughout its storied history, but the 2011 defense was the first one in 26 years to lead the country in total defense, rushing defense, passing defense and scoring defense. The Crimson Tide held 12 of their 13 opponents to 14 points or fewer and smothered No. 1 LSU 21-0 in the BCS National Championship. The shutout win over LSU in New Orleans avenged Alabama's only loss of the season, a 9-6 overtime setback to the Tigers at home in a highly anticipated No. 1 vs. No. 2 matchup. There were 14 Alabama defenders who played in that game who would go on to be selected in the NFL draft. Sophomore quarterback AJ McCarron wrested the starting job from Phillip Sims the first week of the season and wound up being named offensive MVP in the title game after completing 23 of 34 passes for 234 yards against an LSU defense that was also loaded with future NFL talent. -- Chris Low

7. 2012 Alabama

Alabama won its third national championship in four years in 2012 and became the first team to repeat as undisputed national champion since Nebraska in 1994 and 1995. Of Nick Saban's five national championship teams at Alabama, the 2012 club might have been the most balanced on both sides of the ball. The Crimson Tide, led by McCarron, averaged 38.7 points per game, and all 11 offensive starters in the season opener that year against Michigan wound up on NFL rosters. Alabama rebounded from a home loss to No. 15 Texas A&M in November to beat No. 3 Georgia 32-28 in the SEC championship, then destroyed No. 1 Notre Dame 42-14 in the title game. The Tide's perennially strong defense was equally nasty that season, as it held 11 of its 14 opponents to 14 or fewer points. -- Low

8. 2015 Alabama

Coming off a bitter loss to Ohio State the year before in the College Football Playoff semifinals, Alabama stumbled again in the third week of the 2015 season in a home loss to No. 15 Ole Miss, which scored 24 points off five Alabama turnovers. All of a sudden, there were rumblings that Alabama's foundation might be cracking. All the Crimson Tide did from there was reel off 12 straight wins, beating seven nationally ranked teams along the way, to win Saban's fourth national championship at Alabama. Junior running back Derrick Henry rushed for 2,219 yards and 28 touchdowns on his way to winning the Heisman Trophy in what was Lane Kiffin's second season of calling the Tide's offensive plays. Alabama had to hold off Clemson and Deshaun Watson for a thrilling 45-40 victory in the national title game. Saban called for an onside kick in the fourth quarter of that game, and kicker Adam Griffith executed it perfectly, leading to the touchdown that put the Crimson Tide up for good. -- Low

Mark Ingram became Alabama's first Heisman Trophy winner in 2009. Kevin Liles/US Presswire

9. 2009 Alabama

Saban's first national championship team at Alabama remains the only one under Saban to go through a season unbeaten. The Crimson Tide beat four top-20 teams away from home, but none was any sweeter than the 32-13 win over No. 1 Florida and Tebow in the SEC championship. The year before, the Gators and Tebow had ended Alabama's 12-game winning streak by knocking off the No. 1-ranked Crimson Tide 31-20 in the SEC championship. Alabama held seven of its opponents that season to 10 or fewer points, thanks to a defense that finished second nationally in scoring, and sophomore running back Mark Ingram became the first Alabama player to win the Heisman Trophy. The Crimson Tide capped their first national championship in 17 years with a 37-21 victory over Texas in the BCS National Championship at the Rose Bowl, but no play was bigger that season than Terrence Cody's block of a Tennessee field goal attempt as time expired to preserve a 12-10 win over the Vols. -- Low

10. 1999 Florida State

There's no question the pressure was on Florida State in 1999, a year after a disappointing loss to Tennessee in the national championship game. The Seminoles started out ranked No. 1 in the preseason, with a veteran quarterback in Chris Weinke, a star-studded group of receivers led by Peter Warrick, a strong defense that featured Corey Simon, Chris Hope and Derrick Gibson and one of the greatest kickers in college history, Sebastian Janikowski. Midway through the season, adversity hit: Warrick was suspended and fellow receiver Laveranues Coles was dismissed after they got heavily discounted clothes at a department store. Warrick was suspended two games, ending his Heisman hopes. But Florida State kept winning, earning a spot in the national title game opposite dynamic Michael Vick and Virginia Tech. The Seminoles' fast and aggressive defense penned Vick in, and Florida State won 46-29 to become the first wire-to-wire national champion, not to mention Bobby Bowden's only undefeated team. Florida State had four consensus All-Americans, eight All-ACC first-team selections and 31 players who would go on to play in the NFL. -- Adelson

11. 2017 Alabama

For the second time under Saban, Alabama managed to win the national championship without winning the SEC West. The Crimson Tide won their first 11 games but were upended by Auburn in the regular-season finale. The College Football Playoff selection process fell Alabama's way, and the Crimson Tide grabbed the No. 4 seed. After beating Clemson in the semifinals, the Crimson Tide met Georgia in an all-SEC title game that will go down as one of the more thrilling finishes in college football history. Freshman quarterback Tua Tagovailoa came off the bench in the second half and threw a game-winning touchdown pass on the final play in overtime to win it for Alabama. Despite being gutted by injuries at linebacker, Alabama led the country in scoring defense, total defense and rushing defense. -- Low

Hunter Renfrow's TD catch to beat Alabama came with just one second left on the clock. CSM via ZUMA Wire

12. 2016 Clemson Tigers

When the season opened, Clemson debuted a new motto, "Finish with no regrets." After coming up just short in the national title game against Alabama the previous season, the Tigers went into 2016 determined to win it all. With Watson returning to lead the way, along with Mike Williams, Wayne Gallman, Jordan Leggett, Christian Wilkins and Ben Boulware, Clemson was favored to make it back to the College Football Playoff. But Clemson had to overcome some uneven performances and a loss at home to Pitt in early November before making it into the top four. Then, it had to overcome Alabama in the national title game again. How that game ended ranks among the most exciting in championship game history. The lead changed three times in the fourth quarter, and Clemson got the final word when Watson threw the game-winning, 2-yard touchdown pass to Hunter Renfrow with 1 second left on a play called "Orange Crush." -- Adelson

13. 2000 Oklahoma Sooners

The 2000 Sooners weren't Bob Stoops' most talented Oklahoma team. Yet they proved to be one of the most hard-nosed teams of the past 20 years. And that mentality produced an October to remember in Norman. An undefeated season. An improbable run to the national title. And one of the most dominating defensive performances ever in a national championship setting. After years of mediocrity through the 1990s, the Sooners opened ranked 19th in the polls with mild expectations. That all changed in October. Oklahoma obliterated No. 11 Texas, 63-14. Knocked off second-ranked Kansas State on the road. Then rallied from an early 14-0 deficit to hammer No. 1 Nebraska. That three-game run propelled Oklahoma to the Orange Bowl against Florida State, which was a double-digit favorite, thanks to its high-powered offense. But against the Sooners, the Seminoles' offense failed to score, bringing Oklahoma its first national championship in 15 years. While cementing the legacy of the '00 team. -- Trotter

14. 2014 Ohio State Buckeyes

The College Football Playoff arrived in 2014 to determine an undisputed champion. Ohio State left no doubt as to which team deserved that distinction. Seemingly derailed twice -- by a Week 2 home loss to unheralded Virginia Tech and then by a knee injury to starting quarterback J.T. Barrett -- Ohio State staged an incredible run to claim its first national title in 12 seasons. A roster filled with All-America candidates and future first-round draft picks overcame the loss of Barrett, as backup Cardale Jones dazzled in relief. Ohio State crushed Wisconsin 59-0 in the Big Ten title game, then rode running back Ezekiel Elliott to wins over Alabama and Oregon in the playoff. Unanimous All-America selection Joey Bosa anchored the defense along with linebacker Darron Lee and a playmaking secondary featuring cornerback Doran Grant and safeties Vonn Bell and Tyvis Powell. Tom Herman's offense scored 42 points or more in 11 games and reached 50 points six times. -- Adam Rittenberg

15. 2010 Auburn Tigers

His college career might have been fleeting, but quarterback Cam Newton had one of the greatest seasons for a quarterback in SEC history on his way to winning the 2010 Heisman Trophy and leading the Tigers to an unbeaten 14-0 record and their first national championship since 1957. Newton, in his only season at Auburn, was unstoppable. He passed for 2,854 yards and 30 touchdowns and rushed for 1,473 yards and 20 touchdowns. Operating out of Gus Malzahn's no-huddle offense, 6-foot-5, 245-pound Newton was a first down waiting to happen any time the Tigers faced short-yardage situations. The Auburn defense didn't put up overly impressive numbers but was masterful when it came to forcing key turnovers. And in the BCS National Championship Game win over Oregon, defensive lineman Nick Fairley was the difference. The Ducks simply couldn't block him. Fairley finished the season with 24 tackles for loss, including 11.5 sacks, on his way to winning the Lombardi Award. -- Low

USC didn't play for the national championship that season, but the AP poll named the 2003 Trojans champions over BCS champion LSU. AP Photo/Kevork Djansezian

16. 2003 USC

USC ushered in the Leinart-Bush-White era with a 23-0 win at Auburn to open the season and -- outside of a road loss to Aaron Rodgers-led Cal -- remained utterly dominant, on both sides of the ball, the rest of the way. The Trojans ranked No. 5 nationally in scoring and No. 17 in scoring defense and did not win a game by fewer than 14 points (a 28-14 win against Michigan in the Rose Bowl). WR Mike Williams came into his sophomore season as a bona-fide star and was the focal point of the offense with 95 catches for more than 1,300 yards, and White, Bush and Hershel Dennis combined for 1,936 yards rushing. On the defensive line, Kenechi Udeze, Mike Patterson and Shaun Cody all became first- or second-round picks over the next two drafts, and they played in front of one of the best groups of linebackers in the country, led by Lofa Tatupu. The Trojans didn't actually play in the BCS title game, passed over in favor of Oklahoma and LSU, but The Associated Press named USC the champion anyway. -- Bonagura

17. 2003 LSU Tigers

Before building his dynasty at Alabama, Nick Saban returned LSU's program to glory on the Bayou and led the Tigers to their first national championship in 45 years in 2003. It was a team that, in vintage Saban fashion, was built around a ferocious defense. The defensive line, with the likes of Marcus Spears, Marquise Hill and Chad Lavalais, made life miserable for opposing offenses, and the Tigers held eight of their nine SEC opponents that season under 20 points. LSU's only loss that season was to Florida, but the Tigers rebounded by winning their last eight games, capped by wins over No. 5 Georgia in the SEC championship game and No. 3 Oklahoma in the BCS National Championship. LSU wound up sharing the title that season, as The Associated Press had USC No. 1 in its final poll. -- Low

18. 1998 Tennessee Volunteers

The Vols followed up their SEC championship in 1997 with their first national championship in nearly a half century a year later, and did so on the heels of having the greatest quarterback in school history, Peyton Manning, depart for the NFL. Tennessee went unbeaten and became the first national champion of the BCS era. The Vols beat eight bowl teams that season and four nationally ranked teams away from home. But their breakthrough win came in the third week of the season in a 20-17 overtime win at home against Florida, which had beaten Tennessee five straight times. The Vols' defense was led by fiery All-America linebacker Al Wilson, the centerpiece of a unit that held 10 of its 13 opponents to less than 20 points that season, including seven of the nine SEC foes the Vols faced. There were 26 players who played during the 1998 season for Tennessee who would go on to be selected in the NFL draft, including nine of the 11 defensive starters. -- Low

Glenn Dorsey became the first player to win the Nagurski Award, the Outland Trophy, the Lott Trophy and the Lombardi Award in the same season. John David Mercer/USA TODAY Sports

19. 2007 LSU

One of the more improbable national champions, considering LSU lost at home to unranked Arkansas in the regular-season finale, Les Miles' club went on to defeat Tennessee in the SEC championship game and then jumped from No. 7 to No. 2 in the final BCS standings after several upsets that final week, notably West Virginia losing to Pittsburgh. Just like that, the two-loss Tigers were in the BCS National Championship Game and took care of business with a 38-24 win over No. 1-ranked Ohio State. LSU beat seven nationally ranked teams that season, and both of its losses came in triple overtime. The defense was rock-solid, led by Outland Trophy winner Glenn Dorsey at tackle, and running back Jacob Hester was the heart and soul of an offense that scored 30 or more points in 11 of 14 games. It's also a team that is remembered for Miles' free-wheeling gambles, be it the fake field goal against Florida, the last-second touchdown pass against Auburn or the Tigers going for it repeatedly on fourth down. -- Low

20. 2006 Florida

There was plenty of uncertainty about whether Florida would even get into the BCS national title game opposite undefeated Ohio State. The Gators and Michigan had one loss each, and the lobbying for the final spot was intense on both sides. In the end, Florida squeezed in by a hundredth of a point in the final BCS standings, setting up a meeting with the Buckeyes at the Fiesta Bowl. Ohio State went in as a touchdown favorite, and few outside Gainesville gave Florida much of a chance to win. But the Gators' superior speed and athleticism prevailed, as Florida ran circles around the Buckeyes. The quarterback platoon featuring Chris Leak and Tim Tebow worked seamlessly, and a defense led by Derrick Harvey, Jarvis Moss, Brandon Siler and Reggie Nelson shut down Heisman winner Troy Smith. It was Urban Meyer's first national championship team at Florida, but not his best. This team, however, laid the groundwork for what was to come. -- Adelson

21. 2002 Ohio State

No one would label the 2002 Buckeyes dominant, despite five wins by 24 points or more and a defense that allowed only 64 points in the second half all season. Ohio State's signature moment before the famous pass interference call in the title game was a fourth-down touchdown pass from Craig Krenzel to Michael Jenkins that gave the team a 10-6 win over a 4-5 Purdue team. Holy Buckeye, indeed. The Purdue win kicked off a November of escapes for Jim Tressel's team. Ohio State beat unranked Illinois in overtime, then outlasted archrival Michigan 14-9 as running back Maurice Clarett returned from injury and Krenzel led a fourth-quarter touchdown drive. The defense had stars such as safety Mike Doss, lineman Will Smith and Chris Gamble, who played cornerback and receiver. Clarett, a true freshman, became the face of the offense. This was a team that simply knew how to win, style points be damned. -- Rittenberg