Forget parity. With four teams now at 7-0 -- no more than two teams had reached that mark in any previous NFL season -- we have more candidates for perfection than ever before. As we enter Week 9, it's time to ask how likely it is that the 1972 Dolphins finally get some company.
To identify the biggest obstacles that the four teams face on the road to 19-0, as well as their chances of making it to that destination, we look at projections based on Football Outsiders' DVOA ratings (which are explained here) that consider the different paths that the season could take given where all the teams stand right now.