The Kansas City Chiefs and Tampa Bay Buccaneers will have plenty of things in common in Super Bowl LV, starting with a pair of all-time QBs in Patrick Mahomes and Tom Brady. But in many other ways, the teams’ paths to the brink of a championship could not be more different. Because of that, whoever wins will invariably sketch a blueprint for the rest of the league to follow — as difficult as each build might be to emulate.
Kansas City has been playing championship-caliber football for a while now. Starting from an existing talent base that was good enough for a 10-6 record and a close playoff loss with former QB Alex Smith in 2017, the Chiefs turned to Mahomes under center in 2018 and got to another level. Narrowly losing to the eventual champion New England Patriots in the AFC title game, K.C. — which had the league’s fifth-youngest roster1 — had nonetheless made a statement that it would be a force to reckon with in the years to come.
The 2019 Chiefs were even better after addressing some of their big weaknesses from 2018. They added key defensive contributors such as safety Tyrann Mathieu and defensive end Frank Clark, and they subsequently improved from 30th to 13th in schedule-adjusted EPA on that side of the ball. And the offensive core of Mahomes, tight end Travis Kelce and receiver Tyreek Hill remained as dangerous as ever en route to the title. As a result, the Chiefs were one of the better champions in modern NFL history, with a final Elo rating of 1745 — 24th-best among all-time Super Bowl winners.
Going into 2020 as favorites to repeat, the Chiefs clearly took an “if it ain’t broke, don’t fix it” approach to their roster. Only 17 percent of the team’s Approximate Value (AV) came from players who were not with the club a year ago, which ranked 27th out of 32 teams this season. Mahomes was the team’s top passer — and best overall player by AV — for the third consecutive season, while Kelce was K.C.’s leading receiver for the second-straight year. Mathieu, Clark and interior lineman Chris Jones were the team’s three most valuable defenders by AV, just as they were in 2019. Among Chiefs with 5 or more AV, only two — running back Clyde Edwards-Helaire and tackle Mike Remmers — were new to the team in 2020.
The Buccaneers, meanwhile, provide a nice contrast to K.C.’s team-building model. They finished last year with a 7-9 record in coach Bruce Arians’ first season, with a defense that ranked fifth in EPA but an offense that ranked 22nd.2 Going into 2020, Tampa Bay hadn’t made the playoffs since 2007 and had finished with an Elo below 1500 (league average) 13 times in the previous 16 seasons. If the Chiefs had been perennially good in recent years — 2020 was the eighth straight season they finished with an Elo above 1500 — the Bucs had seldom been able to keep their head above water for more than a decade.
What makes Patrick Mahomes so great? | FiveThirtyEight
The 2019 Bucs’ roster clearly had potential. Weighted by AV, it was actually the best collection of pure talent in the league in terms of how highly its players were drafted. But to help convert that promise to performance, Tampa Bay said goodbye to starting QB Jameis Winston in the middle of his prime, replacing him with the 43-year-old legend and 20-year veteran of the New England Patriots. (Brady’s presence alone played a large role in making the Bucs the league’s second-oldest team in 2020, as weighted by AV.)
And despite no other QB ever being remotely successful at that age, Brady put up his best passing efficiency numbers (indexed to the league) and his most AV in a season since 2017. With Brady taking Tampa Bay to the Super Bowl, this is just the 12th time in history that a Super Bowl team will start a QB who before the season had never started for the team. (Brady is on the list twice, which itself is pretty incredible.)3
New starting QBs are rare for Super Bowl teams
For Super Bowl starting quarterbacks, fewest previous career starts for the team going into the season, 1966-2020
|Starts for team|
|Season||Team||Starting QB||In Season*||Before Season|
Beyond Brady and the fourth-ranked EPA passing attack in the NFL, the Bucs finally got their breakthrough because of a defense that ranked third in EPA overall, including fourth against the pass and eighth against the run. That’s slightly better than it was a year ago, despite the fact that only one of their nine best newcomers by AV (rookie safety Antoine Winfield Jr.) was on the defensive side of the ball. Tampa Bay’s journey to the Super Bowl is a tribute to all of those teams who have felt like they were “a quarterback away” from contender status.
The teams’ different philosophies are even reflected in how they spent their salaries this season. Although they’re known for their explosive offense, the Chiefs actually spent the second-most salary cap dollars on defense of any team, according to Spotrac, trailing only the Buffalo Bills. (K.C. spent the ninth-most of any team on offense.) And the Bucs spent the third-most salary cap dollars of any team on their offense, while ranking sixth in spending on defense.
Over the course of the season, the two teams’ competing paths took them through different places in the league’s hierarchy. While the Chiefs’ Elo improved by a modest 76 points from preseason through the conference championship — 22nd-fewest of any Super Bowl team ever — the Bucs improved by a whopping 205 points, 10th-most of any Super Bowl team. And they did the bulk of that improvement — 138 points’ worth4 — since their bye in Week 13.
The most (and least) surprising Super Bowl teams
Largest and smallest changes in Elo rating for Super Bowl teams from preseason to the start of the Super Bowl, 1966-2020
|Largest Changes||Smallest Changes|
|Year||Team||Pre-SB Elo||Change*||Year||Team||Pre-SB Elo||Change*|
In other words, this Super Bowl between Kansas City and Tampa Bay will be a battle between a team we’ve expected to be here for a long time and a team whose rise came much more recently. It will also feature a team that had the right quarterback but improved its defense to reach a championship level versus the team that had the defense but found its QB later. And it will see a team that stuck with its core between seasons face a team that saw a major shakeup at the game’s most important position. We don’t know which formula will prevail — our forecast gives K.C. a slight edge, at 53 percent to win — but we do know that each team-building model has allowed the Chiefs and Bucs to both come within a game of the sport’s ultimate prize.
Check out our latest NFL predictions.