> The numbers 1–n are randomly placed into n boxes in a line. There are n people who are each able to look into half the boxes. While they are allowed to coordinate who looks into which boxes beforehand, they are taken out one at a time to choose which half of the boxes they will peek at. The goal is for the first person to find the number one, the second person to find the number two, and so on. If any of them fail to find their number, the whole group loses. What is the probability they lose if they use the optimal strategy?
I wonder if there's a connection to regular graphs here.