Inspiration
As the legendary Vince Lombardi once said, “If it doesn’t matter who wins or loses, then why do they keep score?”
In a few days’ time, the 6-1 Green Bay Packers will play the 7-0 Arizona Cardinals in a marquee Thursday Night Football game that likely will hold significant implications for playoff seeding.
While the Packers and their fans have become well-known around the league for their long, illustrious history culminating in 13 NFL championships including 4 Lombardi trophies, it is a lesser-known point of trivia that the Cardinals are actually the oldest franchise dating back to 1898. The Packers are comparatively spring cardinals given that they were founded in 1919.
Therefore, as the two oldest franchises (albeit the Chicago Bears were earlier to join the NFL than the Packers, by one season) battle it out this Thursday, I thought it would be a fun exercise create some graphs on the most successful teams in the league on the basis of one simple metric: cumulative all-time regular season win percentage.
All-time NFL Win Percentage
I will keep a track of the regular season win-loss-tie records of all 32 NFL teams from when they first started playing in the NFL to the end of the 2020-2021 season. To calculate win percentage, I will use the typical formula of (# wins + 0.5 * # ties)/ # total games played. Win-loss-tie records will be analyzed on a cumulative basis such that we can see the trend of a team’s performance across a period of time.
To instill a sense of competition in this analysis, we can also find the cumulative win percentage leaders on a year-by-year basis. Given that the majority of teams, especially those in the AFC, did not even exist until the early to late 1960s, it makes no sense to conduct this analysis from the inception of the NFL, as then the Cardinals, Bears, Packers, etc. would be up near the top by default. Instead, I will start anointing Win Percentage Leaders starting from the 1970-1971 season, which marks the first season of the unified AFL-NFL league.
All data comes from Pro Football Reference with the assistance of web scraping.
NFL Win Percentage Leaders
From the 1970-1971 to the 2020-2021 NFL season, there were a total of thirteen coronations of the Regular Season Win Percentage Leader, with seven different NFL franchises laying claim to the title. As the graph with all 32 teams is too crowded for any salient analysis, I will include only the franchises that have made it to the top with regards to Win Percentage.
We see that, of all teams, the Cleveland Browns hold the longest cumulative reign with regards to win percentage, and it’s not even close, as their twenty years at the top is more than double that of the next longest-reigning team, the Miami Dolphins. One funny point is that the final reign of the Browns occurred in the 1997 and 1998 NFL seasons when they were temporarily disbanded!
Founded in 1995, the Jacksonville Jaguars also snuck their way to the top during the 1999 – 2000 season on the heels of their fourth consecutive playoff berth.
It is not surprising that the cumulative win percentage for teams has declined across time as quality of play has become more consistent throughout the league.
Also of note is the stranglehold at the top spot by AFC teams, as it was only since 2009 when the Dallas Cowboys finally took over to represent the NFC. Since then, it has been a series of alternate reigns by the Cowboys and the Bears, with the Green Bay Packers finally making their way to the top this past NFL season. Go Pack go!
Conference and Division Breakdown
Here are the graphs for the AFC and NFC conference, as well as the eight different NFL divisions. Feel free to make your own conclusions. I kept the axes’ ranges the same for each chart for easier direct comparison.
Assorted Teams Win Percentage
Yet more breakdowns by miscellaneous groupings including the Bird Teams, the Cat Teams, the Evil League of Evil, the All-Pennsylvania Squad, the Sixers, and the Old Guard.
Bird Teams: Birds of a feather flock together. Consists of the Arizona Cardinals, Atlanta Falcons, Baltimore Ravens, Philadelphia Eagles, and the Seattle Seahawks.
Cat Teams: Fearless and ferocious felines. Consists of the Carolina Panthers, Detroit Lions, Jacksonville Jaguars, and the Cincinnati Bengals.
Evil League of Evil: The historically successful and maleficent teams of the NFL. Consists of the Chicago Bears, Dallas Cowboys, Green Bay Packers, New England Patriots, New York Giants, Pittsburgh Steelers, and San Francisco 49ers.
All-Pennsylvania squad: The Philadelphia Eagles and the Pittsburgh Steelers, both founded in 1933 and even sharing a team together for a season during the Second World War.
Sixers: The AFL teams founded in the 1960s and those 1960s expansion franchises of the NFL. The former group consists of the Buffalo Bills, Cincinnati Bengals, Denver Broncos, Kansas City Chiefs, Los Angeles Chargers, Miami Dolphins, New England Patriots, New York Jets, Oakland Raiders, and Tennessee Titans. The latter group comprises the Dallas Cowboys, Minnesota Vikings, Atlanta Falcons, and the New Orleans Saints.*
Old Guard: The oldest teams in the league, founded before WWII. Consists of the Arizona Cardinals, Chicago Bears, Detroit Lions, Green Bay Packers, Los Angeles Rams, Philadelphia Eagles, Pittsburgh Steelers, and Washington Football Team.
* I set the start year for the Sixers teams to 1960, otherwise these charts have equal axes ranges.
Reflection
A lot can happen in one hundred years’ time. Who knew the Browns were that dominant! I do wonder which teams will rise and fall in the next century of the NFL. Will there even be American football yet played in 2120?