ALLEN PARK, Mich. -- Matthew Stafford stood on the sideline in Week 5 in a blowout against the Arizona Cardinals, benched by his coach, Jim Caldwell, for the first time in his career. At that point, the questions were obvious.
Was Stafford, in his seventh season, the quarterback of the future for the franchise? What would the Detroit Lions, then the last winless team in the NFL, do with the former No. 1 overall pick after the season?
By the end of the season, Stafford made those answers seem very clear. He morphed into a consistent, efficient quarterback the second half of the season under new offensive coordinator Jim Bob Cooter. Those last eight games showed what he can be when he's in an offense he's comfortable in with a coordinator who sees football the same way the quarterback does.
"I had some good stretches there in 2011, but yeah, I'm playing pretty efficient football right now so that's a positive," Stafford said before Sunday's season finale. "It's probably the most efficient I've been, for sure."
Other than 2011, when he threw for 5,000 yards, this season has been the best of Stafford's career.
Stafford finished with the best completion percentage (67.2) and the second-best passer rating (97.0) and QBR (60.6) of his career. He has his most completions since 2011 (398) while taking fewer attempts than in any other season in which he played 16 games (592).
He finished as a top 10 quarterback in almost every major category: Passer rating (ninth), attempts (seventh, 592), completions (fifth), yards (eighth, 4,262), touchdowns (t-seventh, 32) and completion percentage (fifth).
Most of that was built over the second half of the season with Cooter as his coordinator and against mediocre-to-bad passing defenses. Over the last eight games of the season, the Lions played five of the bottom 10 pass defenses in the league and had three games against pass defenses that finished the season in the top 10.
Stafford was consistent in all of them, throwing multiple touchdowns in seven of his final eight games. Over the second half of the season, he had 19 touchdowns and two interceptions -- the 9.5 touchdown-to-interception ratio third in the league behind Russell Wilson and Cam Newton.
"You go on a stretch and throw 19 touchdowns and one or two interceptions, that's very hard to do," Lions coach Jim Caldwell said. "With his completion percentage where it was as well, you don't find many guys playing like that consistently.
"And it wasn't just two games. It wasn't just three games. It wasn't just four games. So that does lead you to believe that there is some pretty good synergy going on there."
Stafford consistently made smart decisions over the second half of the year. He ran when he needed to, gaining a career-high 159 yards, and rarely forced the ball once he started implementing the changes in the scheme Cooter wanted to make.
Some of it had to do with the offense as a whole, from his clear chemistry with Cooter to better pass protection from the offensive line and a more consistent running game. It's not a coincidence the Lions went 6-2 with Stafford playing well and Cooter calling the plays.
Stafford should receive a large share of the credit. After his latest stretch of good play, his future appears to have an answer, as Lions team president Rod Wood said Sunday that Stafford is "our quarterback."
Now, he has to take what he did to finish the 2015 season and build on it for 2016.