Cardinals General Manager Steve Keim (right) has methodically delved into three different free-agent periods with efficiency in mind.

NFL free agency is intentionally constructed as a boon for players hitting the open market.

For several seasons out of the draft, they are restricted to team-friendly contracts which can pay a fraction of true market value. But open the door and let 32 teams bid at once, and a player will quickly get an idea of what he's worth.

By the time the first few days of free agency had elapsed, mostly non-descript players like cornerback Buster Skrine ($13 million guaranteed from the Jets), linebacker Dan Skuta ($8 million guaranteed from the Jaguars) and wide receiver Dwayne Harris ($7.1 million guaranteed from the Giants) were among those who cashed in.

For general managers, it can be an uneasy game. Even as they identify targets to pursue, it's hard to know which other teams are on the hunt, and what the price tag will ultimately be.

With that as the backdrop, it makes even more impressive the way Cardinals General Manager Steve Keim has handled free

agency. For the three seasons he's been in charge, it's easy to recognize the home run signings, and much harder to point to any moves which have significantly set back the organization.

There have been some moves that didn't work out. Wide receiver Ted Ginn was released after only one season, and it cost the Cardinals $1.5 million in dead money. Linebacker Jasper Brinkley never made a big impact following the addition of Karlos Dansby, while tight end John Carlson didn't make the impact expected in 2014. But in Keim's tenure, there have been many more hits – left tackle Jared Veldheer, Dansby, cornerback Antonio Cromartie, linebacker John Abraham – than misses, and, nearly as importantly, the mistakes have left only short-term monetary concerns.

While it's unknown how this year's free-agent crop will shake out – and Keim could very well add to it in the coming weeks – it's clear his philosophy has not changed.

Keim has not been afraid to dive into the free agent market, but only does so on his terms. The Cardinals signed six players in the first week, including one big fish – three-time Pro Bowl guard Mike Iupati, who inked a five-year deal which can be worth up to $41 million. After that, it was all about value, which is something easier said than done when the demand can be so high.

The way Keim proceeds is by identifying possible inefficiencies in the market. He resists giving lucrative long-term deals to players in their 30s, but has no problem targeting those veterans for a season or two because the price tag can be lower than the expected production warrants. Dansby flourished in his one return season to the Cardinals, and Cromartie, Abraham and linebacker Larry Foote were all key contributors in recent years.

This year's poster child could be 30-year-old linebacker LaMarr Woodley, who signed a one-year deal for $950,000 with the Cards

just one year after inking a two-year, $12 million contract with the Raiders. Woodley was cut after being ineffective and injured with Oakland in 2014, and some question whether he has anything left in the tank.

Keim wouldn't have doled out the millions Oakland did for Woodley a season ago, but is more than willing to take a shot on him this year with so little risk.

"To me, there's always value to dangling that carrot, meaning that these players come in on a one-year deal and there's a lot of incentive," Keim said at the NFL Scouting combine. "And when there's a lot of incentive, it a lot of times brings the best out of players."

Cory Redding is another veteran who the Cardinals brought in to add to the defensive line rotation. He could be this year's Tommy Kelly, an elder statesman who is no longer at his peak, but a guy who can play the game at a high level if he's rotated in effectively.

Keim aims to find the low-cost veterans, and he's also not shy about targeting players who are coming off injury. The Cardinals were reportedly interested in Washington outside linebacker Brian Orakpo as well as Broncos inside linebacker Nate Irving, a pair of players whose 2014 seasons were cut short.

They signed linebacker Sean Weatherspoon, a talented player who has missed much of the past two years with a variety of ailments. Weatherspoon inked a one-year, $3.85 million contract. If he can stay on the field, it could be a bargain, and it's an upside play for both the player and the team.

"I think it's the best deal for both parties," Weatherspoon said. "I'm looking to establish myself – re-establish myself – and show what I can do. It's a great organization that's up and coming. You can see the excitement around this building, and it's something I wanted to be a part of, so I do think it's a good deal for both sides."

Keim's signing of Iupati made the biggest headlines, and if he turns out anything like last year's big free agent addition, Veldheer, it will be a shrewd move. Keim's genius, though, is in constantly searching for the undervalued players. He doesn't deal in the middle of the market much, because those types of deals often backfire.

Right now, the Cardinals have about $9.9 million in salary cap space, according to the NFL Players Association.

There's a good chance some of this year's free-agent signings will work out and some won't. But by keeping the risk low and the potential payoff high, Keim's mastered the art of finding bargains within a process designed to reward the players moreso than the teams.