This question just came to me as I was watching a football game.
There is a football league with 20 teams. Each team has to play every other team at home and away, which means each team will play a total of 38 games. All teams will play a game every weekend, and hence the season lasts for 38 weeks. Now, I am interested in following the 6 teams that are favored to win the league. What is the probability that on any given weekend during the season, there is at least one match involving 2 of my 6 favored teams?
What is the generalized solution for the same problem in a league with N teams and n favorites?