Regression is for older players. But not for QB's going from rookie to 3rd years. Its something stupid that fans say. Young QB's only get better with experience. If they appear worse its because of the players around them or they really weren't that good to begin with and just looked good because of the situation they were in.
WRONG.
Definition of regression: a return to a former or less developed state.
Let's give an example, shall we? In 2015, Bortles had an improved throwing motion. While his decision making was poor that season, he was considerably better throwing the ball. Fast forward to 2016, the biggest knock on Bortles was that he regressed back to the throwing motion he had in 2014 which impacted his play in 2016.
This is regression. Stating this is "impossible" is just flat out wrong. Some QBs get better, some QBs hit a ceiling early, some QBs regress.
How old are you? I feel like I'm talking to a 13 year old with this logic.