I saw someone make an attempt to generate an all-time QB Rating ranking taking into account the era that they played. I really liked the effort, and rather than poke holes in the method I thought I would give it my own shot. Poke away.
Here is what I did.
1. I scrapped all the passing data from 1932 to 2019 from
https://www.pro-football-reference.com/
2. QBs had to make 50 attempts in the season to be included for the year.
3. I created a Z score passer rating for each player based on the season average passer rating and standard deviation. Z-scores are common ways to compare scores on different scales. Comparing QB ratings across eras, or even seasons, is like comparing scores on different scales.
4. I then calculated an average Z score for each player based on all the seasons they played and then converted that Z score back to a passer rating based on 2019 numbers. So what this does in effect is say, given how much better Staubach was from his peers based on each season he played, what would his passer rating look like to be equally better than his peers in 2019.
5. To make the final list the player had to have 500 lifetime attempts.
What this list can't do is adjust for the offensive system, some of which optimize for passer rating while others don't. That's always true though even when comparing players in the same year. Okay here is your top 100 all time.