The World Series The World Series is a "best of 7" situation. That is, the teams play until one team has won 4 games. That might happen if one team wins 4 in a row. But it might take 7 games until that happens. Suppose that sports analysts consider one team a bit stronger, with a 55% chance to win any individual game. Estimate the likelihood that the underdog (the team with only a 45% chance) wins the series.