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

Olympic Badminton

Delegation

110 team lists ยท 975 player entries ยท avg team size 8.9

Read this sport as a comparison between raw coincidence and what team size alone predicts. Here, the real rate is +9.5 points above the birthday-paradox baseline.

Real team lists
20.0%
teams with shared birthdays
Why it matters: This is the headline rate, but it should never be read without team size.
Expected from size
10.5%
from avg team size
Why it matters: This is the fair baseline: what same-size random teams would do.
Gap from expected
+9.5 points
real โˆ’ expected
Why it matters: Positive means the sport has more birthday matches than size alone predicts.
Team lists
110
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 Olympic Badminton, 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 16.4.

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 (9.2 athletes), so their birthday-match rate naturally rises.

By country

Top 40 countries by team-list count.

CountryTeam listsAvg playersReal
KOR912.044.4%
DEN811.637.5%
CHN816.462.5%
JPN810.025.0%
MAS87.325.0%
INA813.350.0%
GBR79.614.3%
THA76.914.3%
GER75.70.0%
AUS66.20.0%
CAN56.60.0%
TPE55.80.0%
POL45.50.0%
USA36.00.0%
HKG35.70.0%
SWE38.00.0%
RUS25.50.0%
IND26.00.0%
NED26.50.0%
RSA25.50.0%
BUL17.00.0%
MRI15.00.0%
SGP15.00.0%
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.

GenderTeam listsRealExpectedGap
Women6618.2%11.4%+6.8 points
Men4422.7%9.3%+13.5 points

Sample team lists

Largest teams in the dataset.

TeamSeasonPlayersRepeatsExpected chance
INA Badminton (1996 Summer) ยท INA1996 Summer20141.1%
CHN Badminton (1996 Summer) ยท CHN1996 Summer20241.1%
INA Badminton (2000 Summer) ยท INA2000 Summer19137.9%
CHN Badminton (2008 Summer) ยท CHN2008 Summer19137.9%
CHN Badminton (2004 Summer) ยท CHN2004 Summer18334.7%
KOR Badminton (1996 Summer) ยท KOR1996 Summer17131.5%
CHN Badminton (2012 Summer) ยท CHN2012 Summer17131.5%
DEN Badminton (1996 Summer) ยท DEN1996 Summer16128.4%
CHN Badminton (2016 Summer) ยท CHN2016 Summer15225.3%
INA Badminton (2004 Summer) ยท INA2004 Summer14122.3%
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.