Unlikely Sweeps

As the playoffs progress into the second round, it may seem surprising that there's only been one sweep so far. It turns out though that even a heavy favorite is more likely to win in five playoff games then to sweep. For example, the most uneven first round series was the Cavs Bulls series. Based off of the power rankings (and a slight home court advantage) the Cavs were supposed to sweep 31.1% of the time (0.32% of the time for the Bulls). 35.5% of the time though they would win in 5 games. So despite all 7 True Hoop stat geeks predicting a sweep, a 5 games series was most likely. It was also what happened.

For the numbers intensive, what sort of power rankings lead to a sweep? Team A must be at least 3.67 times better than Team B for a sweep to be more likely than a four game series. That's a bigger difference than the difference between Orlando, the highest rated team, and Chicago, the lowest rated playoff team. That doesn't mean there won't be any sweeps this playoff, just that I won't be predicting any.