The Chiefs have three superstars leading their dominant offense: TE Travis Kelce was drafted in 2013, WR Tyreek Hill was drafted in 2016, and QB Patrick Mahomes was drafted in 2017. Kansas City’s top three defensive stars — nose tackle Chris Jones, safety Tyrann Mathieu, and edge rusher Frank Clark — were added three different ways.  Jones was second round pick in 2016, Clark was acquired via trade in 2019, and Mathieu was a free agent pickup in 2019.

That 2019 year was a big offseason for Kansas City.  Sure, the team was the #1 seed in 2018, hosted the AFC Championship Game, and only lost in overtime to the eventual Super Bowl champions, but that team was a bit different from this version. Six likely starters in Super Bowl LV — Mathieu, Clark, WR Mecole Hardman, ILB Damien Wilson, G Nick Allegretti, and CB Bashaud Breeland — were added in the 2019 offseason.

The 2019 Chiefs will look pretty similar to the 2020 Chiefs, which is no surprise for a defending Super Bowl champion. Kansas City used its first round pick in ’20 on RB Clyde Edwards-Helaire, and he has been a good contributor and the team’s main back. Veteran tackle Mike Remmers was also added in the offseason, but otherwise, there isn’t much of a difference between the ’19 and ’20 Chiefs other than at the bottom of the roster.

For Tampa Bay, about 25% of the team has been added over each of the last three offseasons.

In 2018, edge rusher Jason Pierre-Paul, C Ryan Jensen, RB Ronald Jones II, S Jordan Whitehead, CB Carlton Davis, and defensive tackles Rakeem Nunez-Roches and Vita Vea were all added.

In 2019, Tampa Bay used the 5th overall pick on LB Devin White, bolstered the pass rush with veterans Shaquil Barrett and Ndamukong Suh, drafted CBs Sean Murphy-Bunting and Jamel Dean in the second and third rounds, and selected WR and NFCCG hero Scotty Miller in the 6th round.

In 2020, the Bucs added six key players: QB Tom Brady, OT Tristan Wirfs with the team’s first round pick, safety Antoine Winfield Jr. with its second round pick, and three big name stars on offense in TE Rob Gronkowski, RB Leonard Fournette, and WR Antonio Brown.

The Bucs also have a few players who have been around seemingly forever: Lavonte David was a 2012 draft pick, William Gholston a 2013 pick, and Mike Evans and Cameron Brate were both added in 2014.  The longest-tenured Chiefs all came from ’13: Kelce, LT Eric Fisher (who will miss the Super Bowl due to injury), and fullback Anthony Sherman.  That makes David the longest-tenured player in the game, but there is one player who was drafted even longer ago by the Bucs or the Chiefs and will be appearing in the Super Bowl.  That’s placekicker Ryan Succup, selected by Kansas City as the final pick in the 2009 Draft, and now Tampa Bay’s kicker.

Using Pro-Football-Reference.com’s Approximate Value grades, I looked at how much AV was produced by each player for both the Chiefs and the Bucs this season. I then calculated what percentage of the team’s 2020 AV was on the roster in 2019, 2018, 2017, and so on. The graph below shows those results:

For KC, 83% of the team’s 2020 AV was on the roster in 2019, but only 57% of the 2020 AV was on the team in 2018. That’s why I noted that the ’19 offseason was the big one for them. For TB, 26% of the 2020 AV was on the team in 2017, 48% was on Tampa Bay in 2018, and 73% was on the roster in 2019.