If you are looking for an upset pick in the first round of the 2011 Stanley Cup playoffs, put your money on the 7th seeds, Buffalo and Los Angeles.
Since the league introduced the 16 team playoff format in 1994, 46.9% of 7th seeds have upset the 2nd seed.
Now that number drops to just 20% when you look at the smaller sample size of playoffs since the 2005 lockout. If you believe the lockout has created a whole new landscape that will better predict upsets, then you need to bet on the 6th seeds, Montreal and Phoenix.
Since the lockout 6th seeds have won a whopping 60% of their series, compared to a 27.3% success rate prior to the lockout. Overall, the likelihood of a 6 seed upsetting a 3 seed is 37.5%.
The 8th seeds have upset the top teams only 28.1% of the time, 30% since the lockout. While being number 1 does give a definite historical advantage, it is far from a comforting number.
I'm not certain you could really call a 5th seed defeating a 4th seed as a true upset. Since the lockout the series is split right down the middle at 50%.