The Vikings’ offensive improvement this season cannot be overstated. Following their 30-23 victory at Detroit on Thursday in which they outgained the Lions 408-289 in total yards, they are fourth in the NFL in total offense at 375.7 yards per game. Last season, they were 28th in the league at 315.1.

And if you want the real reason for optimism about the Vikings’ postseason chances, consider that they are the only team in the NFL in the top five in both total offense and total defense. They rank No. 5 in defense at 290.4 yards per game.

The offense, of course, has been the bigger surprise. One of the main reasons for its success has been third-down conversions. After going 6-for-13 on third downs Thursday, the Vikings lead the NFL with 68 completed third downs and are fourth in in third-down completion percentage at 45.6 percent.

Vikings receiver Adam Thielen is second in the NFL in first-down receptions on third down, according to the Washington Post, with 20, trailing only the 24 of the Chargers’ Keenan Allen.

“Obviously we know as an offense that third downs are huge, for every team,” Thielen said. “It’s something we talked about in the offseason that we needed to get better at third-down conversions. Coaches have done a really good job all season of putting us in really good positions, and our quarterback Case [Keenum] has done such a good job of giving the receivers a chance and letting us make a play.

“That is kind of just what happened on Thursday against the Lions was he trusted us to get open and threw the ball and gave us a chance. We were able to convert some big third downs.”