An obvious shift has taken place in the NFL over a relatively short period of time. Offenses have moved away from a run-first game plan in favor of a more high flying version. This fact was never more clear than in 2011. Teams threw the football more than ever and records were shattered.
To quote Bob Dylan, "The times they are a-changin."
There's no sign that the league is going to revert back to its run-dominated former self any time soon, so if teams don't upgrade their offenses, they'll get left behind.
That's why some teams are scrambling to find players that can transform their outdated offenses to shiny new versions. Tight ends that run like wide receivers (Rob Gronkowski) and wide receivers that are built like tight ends (Calvin Johnson) are highly coveted.
Power running attacks aren't featured much anymore so Christian Okoye-type backs have all but disappeared. Running backs that are speedy and can catch the ball (Darren Sproles) are the new norm.
Some teams have already made adjustments and are leading the way, while others are lagging behind and are struggling to compete in this new era.
The gap might be narrowing, though. Several of these teams took measures to upgrade their offenses that could pay huge dividends.
Here are eight teams that improved their passing offenses the most this offseason.