At a time when NFL defenses are trending toward more exotic alignments designed to confuse quarterbacks, the Vikings remain loyal to a straightforward philosophy that puts players where they traditionally line up.

According to ProFootballFocus.com, which analyzed game tape of every snap for all 32 teams last year, the Vikings ran their base 4-3 defense or their 4-2-5 nickel defense on 96 percent of the snaps in 2010.

Nothing fancy. But the Vikings have ranked in the top eight defensively in four of the five seasons they've used their current Tampa 2-based approach. They have also ranked first against the run three times, second once and ninth last year.

"For us, everything just comes back to being sound and fundamentally right and being right techniquewise," said Vikings coach Leslie Frazier, who was defensive coordinator from 2007 until the 11th game last season. "We've kind of hung our hat on that in the past, and it's been good for us, and nothing has happened to make us feel like we need to deviate from that."

According to ProFootballFocus.com, 18 teams played primarily a 4-3 defense last year. Twelve teams played primarily a 3-4, while Buffalo and Denver played each about half the time.

Because the NFL has become such a passing league, even the 4-3 teams don't just sit in their base defenses. The Vikings, for example, used their 4-3 only 45.8 percent of the time. They used their 4-2-5 nickel defense 50.2 percent of the time. The other 4 percent, they used something other than four linemen.

"You're always trying to disguise something, even in the 4-3, but we're not trying to hide our overall scheme," defensive end Jared Allen said. "At the end of the day, the ball's got to be snapped and people have to make plays. If we're so worried about trying to hide something, then we'll get ourselves out of position to make a play. We're more about just beating the guy in front of us."

Frazier said it's not tempting to experiment with more exotic defenses when he looks around the league and sees what's going on. The Packers, for instance, are a 3-4 team that actually used only two linemen, four linebackers and five defensive backs a whopping 68.6 percent of the time last year.

"We'll do some things in third-down situations when we're three down [linemen] and mixing things up a little bit," Frazier said. "But you still have to be who you are. You have to have an identity and believe in that and you have to stick to it. When you start trying to be what you're not, and I talk to the team about this all the time, that's when you get in trouble.

"We know who we are, we know what we want to be, and then we have to work as hard as we can to execute what we have called or what we have designed to defeat that particular team, but there are teams that ask us some of the things that we're doing and model what they do out of the 4-3 from what we do so it can go both ways if you're having success."