NFL · How Football Changed
How Football Changed
Long-run charts of the NFL: how the game is played, who plays it and what the betting market learned. One new story at a time, each built from public play-by-play, roster and game data.
7 articles · Updated
On this page
The research
The long arc
How NFL offenses changed, across the longest data we can get.
Endangered roles
Jobs on the field that shrank, and the ones that came back.
Bodies by era
Size, height and speed by position and decade.
- Verdict: Data story7 min read
Cornerbacks’ 40 Times Were Flat for 20 Years. Then Every Position Dropped at Once.
From 2000 to 2020 the average combine cornerback ran about 4.50. In 2022 the number fell to about 4.45 and stayed there. Players skipping the drill do not appear to explain it. Every position dropped at the same time, which points to something beyond faster cornerbacks.Updated - Verdict: Data story7 min read
The 300-pound line, and the year it stopped growing
In 1989 one NFL offensive lineman in 14 was listed at 300 pounds. By 1998 it was more than two in three. Then, around 2005, the line stopped getting heavier.Updated
Fourth down and beyond
The decision-making revolution and what it did to special teams.
- Verdict: Data story7 min read
Nineteen Flat Years, Then the Fourth-Down Boom
For 19 seasons, NFL coaches went for it on 4th-and-short about one time in four. Then, starting in 2018, the rate more than doubled. Conversion rates did not budge, and going kept beating kicking.Updated - Verdict: Data story6 min read
The Endangered Punter
NFL teams punted 3.55 times a game in 2025, almost a third fewer than in 1999. Offenses score more, turn it over less and go for it more. The punts that remain are among the best of the 27 seasons on record, by net yards and by how often they pin teams deep.Updated
The market remembers
Decades of results set against what the betting line expected.
What this series is
Football folklore is full of eras: the run-first game, the bell-cow back, the lumbering lineman, the coach who always punted. This series checks each story against the numbers, season by season.
Sometimes the folklore holds. Often the turn came earlier, later or in the other direction than people remember. Each story leads with that answer, then shows the charts behind it.
How the stories are built
- Regular season only, unless a story says otherwise, so changes in playoff format do not move the trend.
- Shares and rates, not totals, so the move from 16 to 17 games in 2021 does not fake a rise.
- Definitions stated up front. Where coding changed (sacks became official in 1982; combine 40s went electronic around 1999), the chart starts after the change or marks it.
- No betting picks. A few stories compare the market with results; none of them is a recommendation.
Put the research to work
Frequently asked questions
Where does the data come from?
Play-by-play, rosters, combine results and schedules come from nflverse, which publishes them under a CC-BY 4.0 licence. Game results before 1999 come from FiveThirtyEight’s public NFL game file (MIT licence), and league passing totals for 1963–1998 are cited from Pro-Football-Reference. Each story lists its exact sources.
Why do most charts start in 1999?
Public play-by-play starts with the 1999 season. Stories that need older data use rosters (back to 1920) or game results (back to 1920), and say where the series begins.
How often is a new story published?
One new story a day while the series runs. Each lands on this page on its publish date.
Sources and method
- nflverse play-by-play, rosters, combine and schedules (CC-BY 4.0)
- nflverse games file (scores, spreads, roof)
- FiveThirtyEight NFL Elo game file, 1920–2021 (MIT)
Research and analysis, not betting advice. Past results do not guarantee future returns; bet only what you can afford to lose.