Rick Spielman is a quality general manager.

Rick Spielman is a mediocre general manager.

You can support either assertion with a roomful of evidence.

Which is proof of that Spielman is a fairly typical NFL general manager.

He helped build the 2009 Vikings, who might have featured the strongest roster in the league. He helped build rosters that, since 2009, have produced a record of 24-39 with zero playoff victories.

He has knockout wins like the drafting and trading of Percy Harvin on one side of his ledger.

He has Christian Ponder and Matt Kalil on the other.

The latter two raise a question:

How long after a general manager drafts a player is he still responsible for that player's performance?

Today, it's easy to call Ponder and Kalil busts. Spielman chose Ponder with the 12th pick in the 2011 draft, and Kalil with the fourth pick in 2012. Ponder may be on his way out of the league. Kalil reached a low point in his career Sunday when he committed three important penalties.

When the Vikings' braintrust chose Ponder, they didn't advertise him as the next Peyton Manning. They sold him as a quality game manager, someone who could produce first downs in an offense featuring Adrian Peterson.

They were desperate to develop their own quarterback, ending two decades of mostly scrambling for the best old free agent on the market.

For two seasons, Ponder was exactly what they said he would be. He cut his teeth in 2011, then helped the Vikings to a 10-6 record and a playoff berth in 2012. Not until opening day of 2013 did Ponder backslide into the erratic play that would ruin his career.

Kalil was a consensus top-five pick. Like Ponder, he came across as a responsible, likeable guy.

As a rookie, Kalil performed even better than expected. He has since regressed.

Is that Spielman's fault? Should we expect general managers to not only identity talent and fill needs but to foresee how a player will handle a smattering of success two or three years in the future?

Take Cordarrelle Patterson. Spielman traded up to take the raw but spectacular receiver with the 29th pick in the 2013 draft. Spielman chose him because of his ability on returns, and because he promised to replace Harvin's versatile skill set.

Patterson became perhaps the best kickoff returner in the NFL as a rookie. In the final six games of his rookie season, offensive coordinator Bill Musgrave began incorporating Patterson into the offense, and Patterson became a threat to score every time he touched the ball.

In his second year, playing for offensive coordinator Norv Turner, Patterson was again spectacular in the season opener. Since then, he has been asked to be a conventional receiver rather than a hybrid, and he has become unproductive.

Is it Spielman's fault that Patterson's remarkable athletic ability has been a focal point of the offensive coordinator's game plan in only seven of his 27 NFL games?

This is a good time to invoke the unifying theory of the NFL: the importance of finding a franchise quarterback.

Rarely in NFL history has a general manager become revered without being tied to a star quarterback.

Bill Polian built championship teams in Buffalo and Indianapolis and now is ESPN's most renowned NFL personnel guru. In Buffalo, he signed Jim Kelly. In Indianapolis, he landed Manning with the first pick in 1998. Without them, he might be running FiredGMs.com instead of working for an organization intent on world domination.

In Brett Favre's first season as a Vikings starter, he made Spielman's roster look superb. In Ponder's first full season as a starter, he helped Spielman's roster look formidable.

When his quarterbacks have performed poorly, Spielman's roster has looked inept.

Now Spielman has tied himself to another first-round quarterback who, like Ponder, has struggled as a rookie.

After eight seasons on the job and a number of quality draft picks, this much is certain:

Teddy Bridgewater's career will define Spielman's.

Jim Souhan can be heard weekdays at noon and Sundays from 10 to noon on 1500 ESPN. @SouhanStribjsouhan@startribune.com