Question

The World Series is a "best of seven" game championship in which up to seven games are played, and one team has to win four games to win the Series. In the 2007 World Series, the Boston Red Sox swept the Colorado Rockies, meaning that they won the series by winning the first four games. If you assume that each team has an equal chance of winning each game, what is the probability of a World Series sweep?

Answer 1

Consider that for each game, each team has the same probability of winning the game, that is, a probability of 0.5 in each game.

For a sweep, the probability for both teams is given by the product of the probability in each game. Taking into account that a sweep if for the first four games, you have:

P = (0.5)(0.5)(0.5)(0.5) = 0.0625

Hence, the probability for a World Series sweep is 0.025, which is equivalent to the 6.25%.