So how should we interpret an undefeated preseason?

Well, we know the Vikings are playing efficiently, confidently and successfully. We also know Thursday night's 19-3 win at Tennessee completed the seventh unbeaten preseason in a franchise history that stretches to 1961.

Next up is the Sept. 7 regular season opener at St. Louis against a Rams team that's missing its starting quarterback, Sam Bradford, who's out for the season with another torn ACL.

So we all can write down 1-0 for the Vikings, eh?

Well …

Before we do that, let's go back to 2001, the last time the Vikings were undefeated in the preseason. They were efficient, confident and were also coming off a trip to the NFC Championship game the year before.

The season opener also was at home against a Panthers team that was starting Chris Weinke, a rookie fourth-round draft pick, at quarterback.

Naturally, the Panthers won 24-13. The Vikings would win only five games that year. As for the Panthers, all they did was end the season on a 15-game losing streak.

But, with that in mind, Vikings fans should be encouraged by this year's preseason.

Defensively, even with a somewhat vanilla approach that's natural for the preseason, coach Mike Zimmer showcased an approach that was more unpredictable up front, tighter in coverage on the back end and just more aggressive and competitive overall.

A year ago, the Vikings ranked last in scoring defense, allowing 30 points per game. For what it's worth, they were No. 2 (12.3) this preseason. Granted, it's preseason. But something good is happening on that side of the ball.

Meanwhile, offensively, the same 11 starters return. But a better and more clear approach at quarterback coupled with the upgrade from Bill Musgrave to Norv Turner at coordinator makes it obvious that the ceiling is much higher this season.

The Vikings were 11th in scoring and third in rushing despite resting their best player, Adrian Peterson, for the entire preseason.

Although one should temper preseason statistics, here are three belonging to the Vikings that fans should feel good about regardless of whether it's preseason or regular season.

Turnover differential: Plus-5. (No. 2 in the league).

Giveaways: 1. (Tied for fewest in the league).

Penalties: 31. (Tied for second-fewest behind only San Francisco's 29).