On paper, the Vikings did nothing to help the offensive line with their top pick in this year's NFL draft.

But football isn't played on paper.

So while the Vikings didn't add a lineman at their first opportunity, they did make their linemen instantly better in Friday night's second round when General Manager Rick Spielman traded up seven spots to select Florida State running back Dalvin Cook 41st overall.

How?

"Dalvin really understands blocking schemes and how to set blocks up and get to that second level and explode," said Florida State coach Jimbo Fisher. "He has a real feel for the game."

Cook was a first-round talent who fell to the second round mainly because of concerns about the crowd he runs with off the field in South Florida. Convinced that Cook is not a character risk, the Vikings targeted him even as only four offensive linemen were being selected in the first 38 picks.

The Vikings took Florida State running back Dalvin Cook 41st overall in a move that promises to help make their linemen better instantly.

This has been a historically weak draft for offensive linemen. A record-low seven were taken in the first two rounds. So at that point, Cook was the best option to help the line improve on last year's league-low average yards per game (75.3) and per carry (3.17).

Things changed in the third round. Sensing a run on offensive linemen, Spielman started the run when he traded a fifth-round pick to move up nine spots and select Ohio State's Pat Elflein, the reigning Rimington Award winner as the nation's best center. He also can play guard, meaning he'll either compete for the opening at right guard or stay at center as Joe Berger moves to right guard.

"One thing I know is we got a lot better in the run game than we were a year ago," said Spielman, who now has seven more picks Saturday after trading down twice in the third round.

Cook is a three-down back who needs work in pass protection and ball security. But he's also a playmaker who averaged 6.5 yards per carry with 48 total touchdowns and 79 receptions in three seasons at Florida State.

Spielman used Adrian Peterson as an example of how a running back can help an offensive line be better than it really is.

In 2012, the Vikings had a good offensive line. Peterson made it great by bulling his way to 2,097 yards and league MVP honors on a playoff team. In 2015, the Vikings didn't even have a good line, but Peterson still led the league in rushing with 1,485 yards.

To those who say the Vikings should have just kept Peterson, we'll say this: He's 32 and missed 13 games last season. Cook is 21. Even Adrian isn't immune to the NFL's circle of life.

"I remember when I was in Detroit and watching Barry Sanders," said Spielman, who worked in the Lions front office. "Just that caliber of running back and the success that he had by his ability to set up blocks and make quick cuts and make things happen on their own."

Cook was asked how he thinks he made his offensive line better at Florida State.

"I just think my vision and putting my O-linemen in the place to make that block," Cook said. "And just making guys miss when they're unblocked. … I think that's what a good running back is supposed to do. And I think that's what I did at Florida State."

Amen, says Fisher.

"He has great eye discipline," Fisher said. "I think that's very important for a back when it comes to training his eyes to look at the right thing. He has the ability to stretch the field as far as stretch runs. He's very disciplined in the run game and has the ability to catch the ball."

Fisher has coached many explosive backs such as current Atlanta Falcon Devonta Freeman. But, he said, "I haven't coached against a back or coached a back that was so dynamic that every time he touched the ball he could score a touchdown."

Any one particular play stand out, Jimbo?

"There's one against Clemson this year," he said. "Dalvin runs a counter play, basically an inside play, and he bounces it outside and the safety has got it. Dalvin gets and angle down the sideline that I thought would be a nice 10- , 12-yard gain. He hit the corner and was gone. That just shocked me.

"There's so many [big plays]. There was a point where he had 12 touchdowns and his average touchdown run was 47 yards."

Yeah, that might help the big fellas a little bit.

Mark Craig is an NFL and Vikings Insider. Twitter: @markcraigNFL E-mail: mcraig@startribune.com