On Reddit, JPAnalyst posted a data viz that shows how, generally, “the best teams decline and the worst teams improve in year N+1”
JPAnalyst also gave some potential reasons for why this keeps happening:
1. Small sample side. Only a 16 (now 17) game season. Variance / luck is a bigger influence
2. Injury luck (good or bad) is not necessarily repeatable
3. Takeaways are extremely influential on wins and are not a sticky stat from year to year
4. The draft is designed for protection (the best teams get lower picks, the worst teams get higher picks)
5. Salary cap avoids dynastic teams (patriots are the outlier)
6. Coaches getting poached from good teams
7. Schedule strength is a factor outside of a teams control and is very influential
8. Record in one-score games. If a team is 6-2 in one score games, they’re not likely to be that’s successful the next year in one score games
Would American football be any better with relegation and promotion? Subjectively, maybe, but I doubt American fans and officials would ever be okay with the prospect of their team dropping out of a “top flight”. Objectively, it could diversify team performances and add a new narrative of risk and excitement. But it’s never going to happen so fans can continue to hope that this season will be their season.
Data viz related: Chartball: a place for sports data nerds to enjoy some data viz