๐ŸŽ‚ Birthday Paradox ยท Sports
โ† All sports

American Football

Team

2,416 team lists ยท 132,926 player entries ยท avg team size 55.0

Read this sport as a comparison between raw coincidence and what team size alone predicts. Here, the real rate is +0.8 points above the birthday-paradox baseline.

Real team lists
91.8%
teams with shared birthdays
Why it matters: This is the headline rate, but it should never be read without team size.
Expected from size
91.0%
from avg team size
Why it matters: This is the fair baseline: what same-size random teams would do.
Gap from expected
+0.8 points
real โˆ’ expected
Why it matters: Positive means the sport has more birthday matches than size alone predicts.
Team lists
2,416
teams analysed
Why it matters: Enough team lists for a useful sport-level read.
What to notice: The best question on a sport page is not "is the real rate high?" but "is it high after accounting for team size?" That is what the gap card is answering.

Country comparison

Countries with the most team lists for American Football, charted by the share of teams with at least one shared birthday.

What to compare: This view is best for spotting sample-shape differences inside a sport. Among the highest-sample countries, USA has the highest observed rate, with an average team size of 55.0.

Gender split inside this sport

Real and expected rates for labelled team lists in this sport.

Why it matters: The gender gap is mostly a team-size story. Men have the larger average team size here (55.0 athletes), so their birthday-match rate naturally rises.

By country

Top 40 countries by team-list count.

CountryTeam listsAvg playersReal
USA2,41655.091.8%
What to notice: Countries with larger average teams will naturally show more shared birthdays. The country list is most useful for finding which samples are driving this sport's overall rate.

By gender

Where the dataset records it.

GenderTeam listsRealExpectedGap
Men2,41691.8%91.0%+0.8 points

Sample team lists

Largest teams in the dataset.

TeamSeasonPlayersRepeatsExpected chance
MIN ยท USA198711516100.0%
PIT ยท USA202411412100.0%
SEA ยท USA198711221100.0%
ATL ยท USA198711120100.0%
PHI ยท USA198711015100.0%
DET ยท USA198711011100.0%
WAS ยท USA198711014100.0%
KC ยท USA198710910100.0%
BUF ยท USA198710815100.0%
CAR ยท USA202410817100.0%
What to notice: The sample team lists show the mechanics: once the player count gets large, the expected chance climbs quickly, and each repeat is another player landing on a date already present.