Rule of 53 is a variation on this nugget from Mike Lombardi: http://www.footballperspective.com/m...ng-in-the-nfl/

If you take only the teams that averaged 50.0 or more rushing attempts + completions per game over the last five years, you get a combined regular season record of 339-189 (.642), with 22 of 33 (66%) teams qualifying for the postseason. That winning percentage puts a team in between 10 and 11 wins per season.