How many teams have won a SuperBowl with a QB on a rookie contract?
Half of the last 8, I believe.
Flacco in 2012, Wilson in 2013, Wentz/Foles in 2017 (I think this counts) and Mahomes this past season.
That also doesn't include teams that made the SB with rookie deals but lost. Kaepernick in 2012, Wilson in 2014, and Goff in 2018.
I'm sure many people have seen the stats already, but here's what it looks like:
Starting with the 1994 season (first year of the NFL salary cap):
No team has ever won a SB having a QB taking up more than 13.1% of the teams salary cap. That high point is from 1994 with Steve Young.
Brady's cap hit in 2018 was actually one of the all-time highs, at 12.2%.
So while history is by no means a predictor of the future, if you were to extrapolate that over the current salary cap, It would mean that you effectively can't have a QB with a cap hit over $26M and expect to win a SB, based on historical data.