Over the last week, I’ve looked at the biggest quarterback declines and quarterback turnarounds when it comes to career records. But there were some limitations in those studies, so today, I want to use a new method.

I assigned 20 games of .500 play — i.e., a 10-10 record — to each quarterback’s record after every start of his career. Then I checked to see which quarterbacks had the biggest declines/improvements in record/rest-of-career record using these metrics.

Let’s take Marc Bulger as an example. He started 95 games in his career. At one point, he was 28-11, which is a 0.718 winning percentage. For the rest of his career, he went 13-43, for a 0.232 winning percentage. If we add 20 games of .500 play to his first stint, that makes him 38-21, which translates to a 0.644 winning percentage. For his rest of career, his record would go down as 23-53, a 0.303 adjusted winning percentage. That’s an adjusted winning percentage decline of 0.341, the most of any quarterback in history.

Also of note: Matt Ryan checks in at #6 in this study, ^[1]Minimum 10 games in both the early and rest-of-career stretches. thanks to a 18-31 record after starting his career at 56-21.

Now let’s look at things the other way, ^[2]Subject to that same 10-game minimum for each stretch., where Steve Young will be our guiding force. The Hall of Fame quarterback began his career for the Bucs with a 3-16 record; he then lost his first start with San Francisco, too. At that point, he had a 0.150 career winning percentage, and an adjusted winning percentage of 0.325. But for the rest of his career, he went 91-32, for a 0.740 winning percentage and a 0.706 adjusted winning percentage. That’s an improvement of 0.381 adjusted winning percentage points, the most ever.

What do you think? Is 20 games of .500 play the right number? And, whether it is or isn’t, what stands out to you?