Mike Tanier has a post at NBC Sports pointing out that Green Bay Packers QB Aaron Rodgers has a career passer rating of 98.4, which is No. 1 on the NFL's all-time list. He's better than any of the great NFL quarterbacks you can name in this statistically category. I knew he was good, but I hadn't realized that he's the best ever!!!
Most of his article is about how the convoluted passer rating is calculated, and how it wasn't designed for the high completion percentages of the modern era. Quarterback friendly rules enacted in 1978, plus the general adoption of West Coast offensive principles, have transformed the game over the past 30 years. All good points and I agree that passer rating isn't the only way to evaluate quarterbacks.
I often use the passer rating to show trends and compare quarterbacks. It's a stat familiar to everyone, and we can tell when a rating is good or bad. In Rodgers's case, it shows that he's been in great in his first three seasons. He's had between the third and sixth best passer rating from 2008 through 2010, but he hasn't been generally viewed as the best quarterback in the league for any single year.
Maybe some day he'll break through with a Tom Brady-esque 50 touchdown season. Or maybe he'll remain one of the top six quarterbacks for the next several seasons, and it will make him look exceptionally good in hindsight. The passer rating doesn't prove he's the best quarterback in NFL history, but it's good indicator that he's had a great start to his NFL career.