Click the green flag. 23 people in the same room, 50% chance that 2 of them share the same birthday. The average matches can represent the probability by brute force.
This project is based on the birthday paradox. (and inspired by Vsauce's video). The birthday paradox states that in a room of 23 people, there is a 50% chance that two of them share the same birthday. And in a room of 75, the probability is about 99.9% that two of them share the same birthday. Vsauce's video on the birthday paradox can explain in much more detail.
