Here’s a Glicko chart for the 2014 NFL season. Tech details and optimizations still to come, but for this version I calculated 2013 Glicko ratings and used them as a starting point for the 2014 season. I also included error bars, which represent a 95% confidence interval for the rating. Essentially, if the bar from one team overlaps with the point from another team, then their ratings are statistically indistinguishable from each other. The dotted gray line is league-average. Check it out:
What I like about this is that it makes it easy to lump the league into three different categories: teams that are clearly above average (everyone from the Seahawks->Packers), teams that are about average (Chargers->Rams), and teams that are clearly below average (Vikings->Bucs). More in-depth analysis might help you distinguish the teams on a more fine-grain scale, but this rough cut is both a good start and a good reminder that we don’t know much after a 16-game season.
Once I get the final version refined (hopefully before the season starts), I’ll roll out a post explaining it in detail. Until then, consider this a work-in-progress.