I'd heard about a stat on TV that listed which NFL teams had the most wins since the start of the 
Free Agency era (the 1993 season) but I couldn't find the stat online. Thankfully nfl.com has stats
going all the way back to 1920. I wrote the script to grab the pages with nokogiri for each year 
of wins/losses/ties from nfl.com and sum those stats up for each team.

To use:
stats = NFLStatParser.new(1993..Date.today.year)
summed_wins = stats.sum_wins_losses
summed_wins.sort_by { |team, wins_losses| wins_losses[:wins] }.reverse