ALLEN PARK, Mich. -- Entering his ninth year in the league, only one player has enjoyed a longer tenure with the Detroit Lions than Matthew Stafford. If last year marked the franchise passing from Calvin Johnson’s hands to Stafford’s, this offseason has been about something else.

It’s been about improvement.

Sure, Stafford has tried to get better every year. Over the past three seasons, the veteran QB has improved his decision-making and leadership markedly, and developed a talent for getting the Lions to run the best play at the best time. He’s become the clear-cut leader of the Lions, both during games and in practices.

While the Lions as a whole have become his team, Stafford has assumed command of the offense in particular, a unit he’s been working himself into the past two offseasons with offensive coordinator Jim Bob Cooter. The offense fits Stafford’s style now -- aggressive, with calculated downfield passing -- and the number of deep plays Detroit has run over the past month are a testament to that.

This brand of offense has still compelled Stafford to improve certain areas of his game.

“Hopefully a lot of things,” Stafford said, when asked what he can do to get better during the offseason. “I’m trying to continue to grow in this offense. I don’t think you ever stop improving. You want to be really good in this game for a long time, you can never settle, and I’m that way.

“I just want to go out there and work as hard as I can, find little things to get better at every day.”

In theory, the little things are where Stafford has made the most progress this offseason. His arm, already one of the strongest in the league, is unlikely to gain more potency. He will likely continue to exhibit the athleticism that made him effective scrambler when necessary last season.

But it’s the nuance of things -- that’s where the Lions have seen a leap from Stafford this spring.

“The little things with getting us into plays, at the line of scrimmage, how he goes about manipulating the cadence, things of that nature,” Lions coach Jim Caldwell said. “Almost in every area he’s been improving and I think that’s a sign of good things to come.”

Stafford has picked up more from an intellectual standpoint entering his ninth season, a stretch that includes 2 1/2 years working with Cooter. He's familiarizing himself with new tight ends Darren Fells and Michael Roberts. He’s making smarter checks, trying to bait defenses into giving him favorable looks so he can use his strong arm to connect with Marvin Jones, Eric Ebron or Golden Tate downfield for a big gain.

Drawing from his near decade's worth of experience in the NFL, Stafford is increasingly able to make split-second decisions in the pocket by recognizing familiar schemes and coverage packages from defenses. And that has allowed him to take more chances.

“It allows you to be aggressive,” Stafford said. “You’re not playing on your heels, you’re playing on your toes. Seeing things from our defense [Wednesday], checking in and out of plays and throwing it down the field.

“We’re not going to hit it every time but shoot, let’s get a good matchup and try to go play and see what happens. That’s kind of what you get from having a lot of experience and a lot of information.

That’s a typical offensive approach from Stafford, who has seen a dip in his yards per attempt since the arrival of Caldwell. Prior to Caldwell’s tenure in Detroit, Stafford averaged over 8.0 yards per attempt in both 2012 and 2013. Since then, the closest he’s come is 7.8 yards per attempt in 2014, followed by 6.44 in 2015 and 7.29 last season.

A lot of those offenses were works in progress, characterized as units undergoing demolition or beginning the process of rebuilding. Now, a semblance of continuity could lead to a more aggressive -- and possibly more productive -- Stafford in 2017.