Nearly every team, every year, improves in the offseason. Regardless of player attrition, teams are adding prospects via the draft, although we won't know how much value they'll provide at the NFL level until they take the field. That said, every team has needs to address and there are finite resources on the free-agent market and in the draft with which to address them. So while it might be hard for a team to "fail" the offseason (which is why you won't find any F's below) there are definitely teams that did a better job than others at filling their needs and adding to the talent on their roster.
The teams I graded with an A were the best at addressing their needs and adding talent for 2013 and beyond. Teams with a B did a good job, but there were still a few areas where I thought they could have improved. Teams with a C I see as treading water. At best they replaced the talent they lost to free agency and retirement. Teams below a C, well, I think they went in the wrong direction this summer. But there weren't too many.
Here are my 2013 NFL offseason grades for the NFC:
Key additions: Carson Palmer, Karlos Dansby, Antoine Cason, Rashard Mendenhall, Yeremiah Bell, Jerraud Powers, Javier Arenas, Frostee Rucker, Lorenzo Alexander, Jasper Brinkley, Matt Shaughnessy, Drew Stanton
Key losses: Kevin Kolb, Kerry Rhodes, Adrian Wilson, Early Doucet, William Gay, Paris Lenon, Quentin Groves, LaRod Stephens-Howling, Greg Toler, Beanie Wells, Brian Hoyer, Adam Snyder, Vonnie Holliday, Anthony Sherman, D'Anthony Batiste, Stewart Bradley, Nick Eason, John Skelton
Analysis: The Cardinals made a lot of good moves this offseason. Arizona's secondary is far different now than it was a year ago -- and in my opinion noticeably better, although what Rhodes brought to the table last season might be missed. That said, Patrick Peterson is on the verge of being a truly elite NFL cornerback.
What is most interesting to me about the Cardinals' offseason is their defensive front seven moves indicate that we are going to see far more 4-3 from this defense going forward -- an excellent idea considering their personnel.
Darnell Dockett can be among the best 3-technique defensive tackles in the league with Dan Williams as a solid nose tackle type in a 4-3. At defensive end, Calais Campbell will excel on the strong side while the combination of Rucker, Shaughnessy and especially Okafor should fit well opposite Campbell. The Cardinals would not have invested the resources they did in Kevin Minter and then Dansby to only play one of the two a high percentage of the time. Of course, Daryl Washington is facing a suspension, but he is equipped to be an outstanding 4-3 weakside linebacker when he returns. Dansby has experience (in Arizona) on the strong side and Minter is a perfect fit in the middle.
Bruce Arians historically likes to employ a lot of double tight end sets, but the personnel on offense right now isn't ideal for that formation. Instead, look for the Cardinals to use a very high percentage of 11 (1 RB/1 TE) personnel, even on early down-and-distance situations. While Arizona's receivers are more or less the same, the protection and quarterback are not.
Contrary to popular belief, the Cardinals are not that bad off at offensive tackle, with Levi Brown on the left side and the vastly improved Bobby Massie on the right. Guard was a huge problem for Arizona last season and they addressed that issue by landing an absolutely superb prospect in Jonathan Cooper and later drafting the athletic Earl Watford. Palmer needs a clean pocket, especially to go deep downfield as this new scheme will stress. Palmer should get more help in that area this year.
The Cardinals also made huge changes at running back and have taken the approach of throwing several players at the problem to see who emerges. I love what Arizona has done this offseason.