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Olympic Swimming
Team
40 team lists · 238 player entries · avg team size 6.0
Read this sport as a comparison between raw coincidence and what team size alone predicts. Here, the real rate is +3.4 points above the birthday-paradox baseline.
Real team lists
7.5%
teams with shared birthdays
Why it matters: This is the headline rate, but it should never be read without team size.
Expected from size
4.1%
from avg team size
Why it matters: This is the fair baseline: what same-size random teams would do.
Gap from expected
+3.4 points
real − expected
Why it matters: Positive means the sport has more birthday matches than size alone predicts.
Team lists
40
teams analysed
Why it matters: Small sample: treat the rate as a lead, not a verdict.
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 Olympic Swimming, 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, CHN has the highest observed rate, with an average team size of 5.7.
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. Women have the larger average team size here (6.2 athletes), so their birthday-match rate naturally rises.
By country
Top 40 countries by team-list count.
| Country | Team lists | Avg players | Real |
|---|---|---|---|
| AUS | 7 | 6.3 | 14.3% |
| USA | 7 | 7.0 | 14.3% |
| CHN | 6 | 5.7 | 16.7% |
| CAN | 5 | 6.0 | 0.0% |
| GBR | 5 | 5.2 | 0.0% |
| FRA | 4 | 5.5 | 0.0% |
| ISR | 1 | 5.0 | 0.0% |
| GER | 1 | 5.0 | 0.0% |
| ITA | 1 | 6.0 | 0.0% |
| KOR | 1 | 6.0 | 0.0% |
| NED | 1 | 6.0 | 0.0% |
| SWE | 1 | 5.0 | 0.0% |
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.
| Gender | Team lists | Real | Expected | Gap |
|---|---|---|---|---|
| Women | 19 | 5.3% | 4.5% | +0.7 points |
| Men | 21 | 9.5% | 3.7% | +5.8 points |
Sample team lists
Largest teams in the dataset.
| Team | Season | Players | Repeats | Expected chance |
|---|---|---|---|---|
| Australia - Women's 4 x 100m Medley Relay · AUS | 2024 Summer | 8 | 1 | 7.4% |
| United States of America - Men's 4 x 200m Freestyle Relay · USA | 2024 Summer | 7 | 1 | 5.6% |
| People's Republic of China - Men's 4 x 100m Medley Relay · CHN | 2024 Summer | 5 | 1 | 2.7% |
| United States of America - Women's 4 x 100m Medley Relay · USA | 2024 Summer | 8 | 0 | 7.4% |
| Australia - Mixed 4 x 100m Medley Relay · AUS | 2024 Summer | 8 | 0 | 7.4% |
| United States of America - Mixed 4 x 100m Medley Relay · USA | 2024 Summer | 8 | 0 | 7.4% |
| United States of America - Men's 4 x 100m Medley Relay · USA | 2024 Summer | 7 | 0 | 5.6% |
| Canada - Women's 4 x 100m Medley Relay · CAN | 2024 Summer | 7 | 0 | 5.6% |
| People's Republic of China - Women's 4 x 100m Medley Relay · CHN | 2024 Summer | 7 | 0 | 5.6% |
| United States of America - Women's 4 x 200m Freestyle Relay · USA | 2024 Summer | 7 | 0 | 5.6% |
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.