Bill James, that takes the square of team points, and divides it by the sum of the squares of team points scored and allowed. The 2011 edition of Football Outsiders Almanac states, "From 1988 through 2004, 11 of 16 Super Bowls were won by the team that led the NFL in Pythagorean wins, while only seven were won by the team with the most actual victories. Super Bowl champions that led the league in Pythagorean wins but not actual wins include the 2004 Patriots, 2000 Ravens, 1999 Rams and 1997 Broncos." Although Football Outsiders Almanac acknowledges that the formula had been less-successful in picking Super Bowl participants from 2005-2008, it reasserted itself in 2009 and 2010. Furthermore, "[t]he Pythagorean projection is also still a valuable predictor of year-to-year improvement. Teams that win a minimum of one full game more than their Pythagorean projection tend to regress the following year; teams that win a minimum of one full game less than their Pythagoerean projection tend to improve the following year, particularly if they were at or above .500 despite their underachieving. For example, the 2008 New Orleans Saints went 8-8 despite 9.5 Pythagorean wins, hinting at the improvement that came with the next year's championship season." DVOA results Each year, Football Outsiders calculates the best and worst teams, per play, with the DVOA metric (see above). Below is a list of the highest- and lowest-rated teams in the league in each year from 1985-2019. Pro Football Prospectus and Football Outsiders Almanac From 2005 through 2008, Football Outsiders published the Pro Football Prospectus book each year before the football season began. It included an essay for each team analyzing the previous season, evaluating off-season moves, and projecting future performance. In 2009, Football Outsiders did not publish a Pro Football Prospectus volume, but instead produced the self-published Football Outsiders Almanac 2009. The reason for this is explained in the book: So why the name change, and why aren’t we in bookstores? For those who don’t know, our first four books were published through an agreement with Prospectus Entertainment Ventures, the company that owns Baseball Prospectus (as well as the expansion projects Basketball Prospectus and Puck Prospectus). It was PEV that had the publishing contract (first with Workman, then Plume). This year, for various reasons, Plume decided they no longer wanted to publish books related to other sports besides baseball. Other publishers were interested