The Vikings defense had much to do with the surprising 10-6 run to the playoffs for 2012. The main lament heard often during the offseason was the failure of that defense to produce turnovers.

The Vikings had a total of 22 takeaways last season, with only 10 of those on interceptions. The team leaders were veteran cornerback Antoine Winfield and rookie safety Harrison Smith with three apiece.

Winfield was the Vikings' best cornerback in 2012, and his departure left skeptics asking, "Where will the interceptions come from this season?"

At the season's quarter pole, they have come from everywhere — two for Smith, two apiece for linebackers Erin Henderson and Chad Greenway, and one for lineman Kevin Williams, for a total of seven.

The Vikings also have five recoveries of forced fumbles for 12 takeaways. That's the fourth-highest total in the NFL. The three teams in front of them — Kansas City, New Orleans and Seattle — have played five games to the Vikings' four.

"We're doing a great job creating turnovers," Smith said Wednesday at Winter Park.

And then the safety added the disclaimer: "Our problem has been allowing big plays. We know that the players are here for a great defense, if we cut out the big plays."

The Vikings defense was in the process of allowing a third consecutive opponent to drive the field at the end of the Sept. 29 game in London.

It had happened in the second game when the Bears went 66 yards in 10 plays and scored with 10 seconds left for a 31-30 victory. It happened a week later in the home Dome when Cleveland went 55 yards in 11 plays and scored with 51 seconds left for a 31-27 victory.

Now, here was Ben Roethlisberger leading Pittsburgh toward a tying touchdown in the closing seconds, from Pittsburgh's 22 to the Vikings' 6, when Everson Griffen forced a fumble and Williams recovered for a 34-27 victory.

The Vikings had a bye week to respond to what they had seen through the first fourth of the schedule. Many saw this as an opportunity to make a deal with Winfield and get Josh Robinson out of the defensive slot, where he was getting toasted.

General Manager Rick Spielman decided to spend his money elsewhere. Quarterback Josh Freeman became available through the idiocy of the Tampa Bay Bucs, and the Vikings won the competition to sign him.

The $2 million-plus in precious salary cap space that could've gone to Winfield was used on a 25-year-old quarterback with big talent, and at no cost in personnel.

What signing Freeman meant was no immediate assistance for a defense that was more of a problem in the Vikings' 1-3 start than the play of Christian Ponder (the quarterback for the 0-3 start).

The Vikings have surrendered an average of 430.8 yards per game. That's 30th in the league, ahead of only Washington (440.5) and Philadelphia (434).

They have been mediocre against the run, allowing 4.2 yards per attempt, and inept against the pass, allowing 326 yards per game.

"I feel like we progressed some against the Steelers, even though Roethlisberger had quite a few yards [383]," middle linebacker Erin Henderson said. "The problem has been stopping teams on third down. We have to start getting off the field."

The Vikings defense has faced third down 55 times and allowed 26 first downs. That's not much worse than opposing defenses — the Vikes are 21-for-54 on third down — but it's a dramatic falloff from 2012.

The Vikings allowed teams to convert on third down at 34 percent (95-for-230) last season. This year, the Lions, Bears, Browns and Steelers — not exactly the murderer's row of the NFL — have converted at 47 percent.

You can talk about getting off the field on third down. How does it happen?

"You execute the defense," Henderson said. "You don't get out of position. You make plays. You don't miss tackles. You don't get penalties that get the other team off the hook. That's how it happens."

It would've been nice to have Winfield to help on Sunday when Carolina's Cam Newton breaks out of the pocket. The money went instead to Freeman, and it's hard to argue with that.

Patrick Reusse can be heard 3-6 p.m. weekdays on AM-1500. preusse@startribune.com