23 and Football Birthdays

Alex Bellos discusses how the Incans used knots in string (Quipu) to record numbers.Check out Brilliant (get 20% off their premium service): https://brillian...

What's the probability that two people on the football/soccer pitch share a birthday?

That's only 23 people (22 players and the ref, as long as there have been no red cards or injuries!!!) and there are 365 days in a normal year.

Dr James Grime explains. Our thanks to Nottingham Forest Football Club.