There was some angst in Yankeeland after the team failed to close out the Angels in game 5. However the Yankees would appear to still be in pretty good shape returning home up 3 games to 2 in the best of 7 American League Championship Series (ALCS).
This suggests the following puzzle. Suppose the Yankees will win each game with probability p (independent of the results of the other games). Then in a best of 7 playoff how large does p have to be for the Yankees to be worse off leading 3 to 2 than they were at the beginning before any games were played.