Four years ago, I wrote about Matthew Stafford and his poor record. At the time, his career mark stood at 17-28 and he had just received a big money extension. In that piece, I noted that his career record was not predictive of much. Well, four years later, and Stafford just received another big money extension. And over the last four years, Stafford has gone 34-30. That’s not great, but it’s not bad, either.

But what’s notable about the Lions offense over the last four years is how reliant on Stafford the team has been. Since 2013, no team has rushed for fewer yards than Detroit, and the Lions also rank 30th in yards per carry. The Detroit offense goes as Stafford goes, and while the former number one pick hasn’t been the best quarterback in the NFL, he’s been pretty valuable.

Stafford became the youngest player to join the 30,000 yard club, which is a function of (1) how young he was when he entered the league, (2) the era he plays in, (3) the pass-happy offenses he has led, and (4) his talent/ability. Stafford played with Knowshon Moreno at Georgia and both were drafted in the first round of 2009. Steve Young didn’t make his first Pro Bowl until his age 31 season. Warren Moon didn’t make his first Pro Bowl under age 32.

In other words, there may still be room for him to improve. For his career, Stafford has been the most average passer in NFL history in terms of era-adjusted passer rating. But what the Lions without him? Detroit is 27-21 over the last 3 seasons, with Stafford putting together 15 game-winning drives and 16 4th quarter comebacks over that period. Detroit replaced Calvin Johnson with Marvin Jones and the offense kept on humming. Without Stafford, the Lions would be one of the weaker teams in the NFL. I don’t know if he deserves a 5-year, $135M contract extension, but at 29 years old, Stafford is still in the prime of his career. For reference, former number one pick Vinny Testaverde was still in Tampa Bay during his age 29 season. Another former first overall pick, Alex Smith, had yet to take a snap with the Chiefs until his age 29 season. Stafford has been around forever, but he’s still so young that the Lions not only had to lock him up, but are still lucky to be able to do so.

Smith and Testaverde are former number one overall picks at quarterback who made a Pro Bowl in their thirties. So, too, are Eli Manning, Carson Palmer, Michael Vick, Peyton Manning, Drew Bledsoe, John Elway, and Troy Aikman. Stafford appears to be in both great physical condition and great health, and with his arm, he can certainly afford to lose a bit of physical ability and still be a top flight quarterback. Based on the history of aging for players like Stafford, I think the Lions can rest comfortably after agreeing to this extension, even if Stafford is overpaid relative to the premier quarterbacks in football.