It's not hyperbole: Andrew Luck's stunning decision to move on from the NFL is the most shocking retirement American pro sports has seen since Michael Jordan left the NBA in 1993. The circumstances are obviously different, and we've seen players like Barry Sanders and Calvin Johnson leave the game earlier than anybody would have expected, but 29-year-old quarterbacks in the prime of their careers just don't get up and leave. This isn't a franchise-altering decision. It alters the entire complexion of the NFL.
To put this in context, by Pro Football Reference's Approximate Value statistic, there have been two players in NFL history who have posted a better season in their final NFL campaign than the Indianapolis Colts quarterback and then retired by choice before turning 30.