Vikings Insider: Some square pegs have fit in, some not

Evolution is nature's way of putting a square peg in a round hole. Eventually, the biological organism will adapt to meet the changing demands of its environment. (Or, it will die, but let's not be so morbid on a holiday weekend.)

In some ways, the Vikings' past 26 games seem written by Charles Darwin.

One of the most consistent criticisms of coach Brad Childress' regime have been attempts to shoehorn players into specific schemes, remaining rigid even if it appeared their skill sets didn't match the requirements. Midway through Childress' second season, it is safe to say the fittest have survived while others still are trying to squeeze into that round hole.

The biggest success story is along the offensive line, which underwent a personnel and schematic overhaul last year. None of the starters had played alongside each other, and all of them were learning a zone-blocking scheme that assigns players an area rather than a specific defender.

At the very least, the approach was different from the one that made left guard Steve Hutchinson an All-Pro in Seattle. It wasn't a natural fit for center Matt Birk, who made his name as a sure-footed player fast enough to lead a screen, and it seemed a disaster for left tackle Bryant McKinnie, who often seemed unsure of his assignment.

Even right guard Anthony Herrera, a starter in 2005, essentially took a redshirt year to learn the scheme. Herrera played in only two games last season -- during which he said coaches "broke me down and built me back up" -- and wasn't ready to start again until Oct. 14, (2007) at Chicago.

While it still might not be the scheme of choice, these players have learned to make it work. Beginning with the Bears game, the Vikings have averaged 206.5 rushing yards per game. Those are wishbone, 1980s-era Nebraska numbers, not the kind of production you see against NFL defenses.

Some of that yardage can be attributed to the unique talents of rookie Adrian Peterson, but he and backup Chester Taylor have been running through wide-open holes of late. The best evidence of the line's improvement is Taylor's 164-yard performance last week against Oakland, the kind of game he never produced as the starter in 2006.

While offensive linemen have learned to zone block, Chris Kluwe has transformed from a kick-it-as-far-as-you-can guy to a directional punter who coordinates coverage with the returner's fielding position. Kluwe struggled at times last season, but through 10 games in 2007, he leads the NFL with 24 punts downed inside the 20-yard line. Kluwe still is utilizing his strong leg, having tied a team record with 22 punts of 50 or more yards in a full season.

Not everyone has adjusted, however. Safety Darren Sharper, who made the Pro Bowl as recently as 2005, has been invisible in some games and a step slow in others.

Sharper's best skill is anticipating a quarterback's thought process to snag interceptions. He tied a career high with nine interceptions in 2005, but he has managed six in the 26 games since, including two this season.

He is not an ideal fit for a Tampa-2 scheme that asks safeties to fulfill their position's name literally: defend half the deep field in hopes that no receiver makes a big play over top of them.

It is an important role but doesn't lend itself to making game-changing interceptions. That is a source of consistent frustration for a player who ranks sixth in NFL history with seven interception returns for a touchdown.

Sharper has voiced his concerns publicly and privately, and it has been reflected in his play. You probably noticed Sharper's admirable but ill-fated exuberance lead to a Green Bay touchdown if you were still watching in the fourth quarter of the Vikings' 34-0 loss at Lambeau Field earlier this month.

Cornerback Cedric Griffin had receiver Ruvell Martin covered and was in position to intercept a Brett Favre pass in the end zone. But Sharper, chasing the ball, inadvertently collided with Griffin and knocked the ball into Martin's hands for Green Bay's final touchdown.

Sometimes, the square peg can't change.

Kevin Seifert • kseifert@startribune.com