Why Super Bowl contenders need impact from young stars, but not necessarily rookies

To win a Super Bowl, teams need their draft picks to overperform the value of their contracts while they are still on their scaled rookie deals.

The Eagles were able to build a Super Bowl winner last season in part because quarterback Carson Wentz had a salary-cap hit of just over $6 million, a pittance compared to other quarterback cap hits. It enabled the Eagles to build up their roster in other places, specifically on defense.

But with the Vikings rookies reporting to camp this week to a team with title aspirations, just how much of a contribution do Super Bowl winners need from that group in their first NFL season?

Looking back at the past 10 champions, the numbers suggest that if you're going to win it all, rookies don't necessarily have to make a big impact.

Pro Football Reference has a statistic called Approximate Value (AV), which is football's equivalent of baseball's WAR (wins above replacement). It attempts to use a single number to quantify a player's contribution to a team regardless of his position. There are a number of factors that contribute to a player's AV — how many games he started, his individual statistics, did he make the Pro Bowl or All-Pro team, how good was the offense or defense of which they were a member? Using all these factors, each player is given a number to represent his value.

For context, defensive end Everson Griffin led the Vikings in AV last season at 15. He was tied for ninth in the league and was four behind the leaders at 19 — Patriots quarterback Tom Brady and Rams running back Todd Gurley. Quarterback Case Keenum had an AV of 14. Linebacker Eric Kendricks had a 10 while tight end Kyle Rudolph and cornerback Trae Waynes were fives. Players such as receiver Michael Floyd and cornerback Marcus Sherels were ones.

The 2010 Packers were tops among the past 10 Super Bowl teams in total AV from their rookie class with 28 thanks in large part to tackle Bryan Bulaga, who compiled an eight that season.

Every team fell between six and 28, with the Eagles coming in fourth at 20 (the Vikings had a rookie class AV of 23 last season). The 2016 Patriots were second at 26, but where they got a big lift was from the 2015 draft class and undrafted free agents, who combined to contribute an AV of 39.

The Eagles got significant contributions from non-rookies on rookie scale deals such as Wentz but also got a lot of production from players in the sixth year of their careers, with that group compiling a total AV of 68. That included players such as receiver Alshon Jeffery (eight) and defensive tackle Fletcher Cox (14).

So while there might be high hopes for Vikings draft picks such as cornerback Mike Hughes or offensive tackle Brian O'Neill, it's possible for the Vikings to contend without a deep impact this season from their rookies. With a lot of players returning from last season, plus the addition of Kirk Cousins at quarterback, the pressure should be off the newbies from having to be major players right away.

Chris Hine is the writer for North Score, the Star Tribune's sports analytics beat: startribune.com/northscore. E-mail: chris.hine@startribune.com