To understand why the Patriots are comfortable letting Wes Welker walk to Denver while replacing him with Danny Amendola, you have to go back to March 2007 and appreciate what led the Patriots to Welker in the first place.

When Bill Belichick dealt second- and seventh-round picks to the Dolphins to acquire Welker in 2007, he wasn’t bringing in a player with much of a pedigree. Welker went unselected in the 2004 draft, and while he made the Chargers out of training camp, San Diego cut him after the opening week of the season. Every team in the league got a second chance to acquire Welker for free, and each of them passed. Welker cleared waivers and made it to the Dolphins, where he spent one year as a returner and special teams grunt before eventually working his way into regular offensive reps. Unable to beat out the immortal Chris Chambers and Marty Booker for spots in a below-average passing attack, Welker started just three games during his three seasons in Miami. He caught 96 passes for 1,121 yards and one touchdown. Not in his last year. Across all three years.

Belichick treats second-round picks like they’re manna from heaven, and he dealt a second-rounder and a seventh-rounder to the Dolphins to acquire Welker. Don’t look back at that decision with what we know about Welker now; look back at it with what we knew about Welker at the time. He was hardly a sure thing; he was a receiver perceived to be a situational player with limited upside, Brandon Stokley with a fumbling problem (12 on 390 touches in Miami, a total that he matched over 817 touches with New England). Belichick didn’t sign Welker for what he was. Belichick signed Welker for what he thought Welker could be.

Forgive me for sounding like Amendola’s agent again for a moment, but his professional résumé before joining the Patriots simply blows Welker’s pre-Pats career away. There are some similarities, of course. After the career at Texas Tech, Amendola went undrafted and became a practice squad guy, bouncing around the Cowboys and Eagles for about a year before eventually catching on with a bad team. The Rams used Amendola as a return guy before pushing him into the lineup as a situational receiver out of the slot. Unlike Welker, Amendola was the focal point of the Rams’ passing attack, leading them in most receiving categories (including targets) in 2010. After missing virtually all of 2011 with a torn triceps, Amendola’s 11-game season in 2012 prorates out to a 91-catch, 968-yard campaign. He’ll join the Patriots with more than twice as many career catches and nearly twice as many yards as Welker had when he joined. He also won’t cost the team a draft pick and has just $10 million guaranteed on his five-year deal, which is less than what Welker received as part of his two-year pact with the Broncos.

The biggest dig on Amendola is his health, but even that’s been distorted in the analyses I’ve seen of this swap. Amendola suffered one major season-ending injury during his time with the Rams, a dislocated elbow. Over that same four-year stretch, Welker suffered one major season-ending injury, a torn ACL against the Texans. Amendola had the misfortune of suffering his injury in Week 1, while Welker’s injury came during Week 17, allowing him to recuperate during the offseason before returning (as a limited version of his former self) without missing any regular-season games. This should go without saying, but you don’t get to choose when you go down with a season-ending injury. The timing of each player’s injury means something in terms of their past availability for their respective teams, but those two injuries are of equal relevance in predicting their future availability for their new teams. In fact, if anything, the Welker injury is scarier; a torn ACL for a player in his early-30s is much more worrisome than a dislocated elbow for a player in his mid-20s. Signing Amendola also doesn’t preclude the Patriots from drafting another slot receiver in the late rounds (or signing one as an undrafted free agent) and attempting to develop him into a possible replacement if Amendola does go down with an injury.

What this eventually boils down to is the innate fear of change that fans have with regard to their team’s stars. Most people are loath to give up on something good until it’s been proven that a once-productive player can no longer perform at the same level. That’s understandable, but it’s a terrible way to run a football team. Belichick knows that, and he’s spent 13 years moving on from players at exactly the right time. Patriots fans probably remember the case of Lawyer Milloy, who was released just before the 2003 season before catching on with the Bills and leading them to a 31-0 victory over the Patriots in Week 1. The Patriots went 17-1 after that and won the Super Bowl. When it wasn’t Lawyer Milloy, it was Randy Moss. Or Ty Law. Or Richard Seymour. Or Deion Branch. Or Adam Vinatieri. At some point, Belichick might deserve the benefit of the doubt in these situations.

This all shouldn’t really be much of a surprise. Belichick has had two years to give Welker a long-term contract and hasn’t expressed even the slightest bit of interest in doing so. Having reportedly been given the final shot at matching what most people characterize as a modest two-year deal from the Broncos, Belichick turned the opportunity down. The Patriots are not built on getting every last drop out of their older players until they can no longer go. They’ve been built by having one constant — Tom Brady — and otherwise relying on change. They’re the team that drafted one guy with a bum back and another who couldn’t stop smoking weed and turned them into the most devastating set of tight ends in league history, a one-two strategy that teams around the league have tried to emulate since. They’re the team that bought low on Moss and went to a scheme with spread characteristics before anyone else in the league had the balls to do so. And they’re the team that went after Welker when he was a backup on a bad offense and ended up getting 672 catches and five Pro Bowls of output before moving on. Welker will very likely play well in Denver, as he’ll spend two years catching passes from Peyton Manning in an offense that might even suit him better than the one he’s leaving. But the Patriots will do just fine without him. They always do.

Out Like a Lion

When the Lions hired Jim Schwartz to be head coach and lead their charge back from that miserable 0-16 season of 2008, they started to build a team that was in Schwartz’s image. During his time as the defensive coordinator in Tennessee, Schwartz went through several different styles of 4-3 before eventually settling on a unit that tried to get as much pressure as possible while rarely blitzing. The Titans built a deep, productive front four around Albert Haynesworth while settling mostly for afterthoughts and projects in the secondary, hoping that the pass rush would get pressure with four and that dropping seven players would cut off throwing lanes.

You can probably see the parallels in Detroit, where Ndamukong Suh was the new Haynesworth, Louis Delmas was the new Michael Griffin, and Kyle Vanden Bosch was … well, an older Kyle Vanden Bosch. The Lions invested heavily in their front four, adding Vanden Bosch in free agency, developing and then franchising end Cliff Avril, and using a first-round pick on tackle Nick Fairley. The secondary was consigned to the bargain bin, as the Lions bought low on failed high draft picks (Chris Houston, Alphonso Smith), stretched bizarrely limited players into roles they couldn’t handle (Jason David, C.C. Brown), and waited for talented, injury-prone players to get healthy (Louis Delmas, Leigh Bodden). If you watched a Lions game during the past few years, you know how this ended up: The experiment failed.

After falling out of the playoffs and diving all the way to 4-12 last season, the Lions pulled the plug on the Schwartz plan. Perennially cap-strapped by the huge rookie contracts bestowed upon Suh, Calvin Johnson, and Matthew Stafford by the league’s old CBA, the Lions decided to radically change the makeup of their roster. They’re attacking their weaknesses, but in the process, they’re removing the few strengths they had.

Both starting ends on that defensive line are now gone. Vanden Bosch was cut after accruing just 15.5 sacks over three years with the team, while Avril was allowed to leave for Seattle on a two-year, $15 million deal that represents a paycut from his $10.6 million franchise number from 2012. Backup tackle Sammie Lee Hill also left for the Titans on Wednesday, and the reinforcements aren’t too exciting: Rotational player Jason Jones was signed to likely start at one defensive end spot, with the other one still unfilled. There’s little promise of a pass rush beyond the interior rush of Suh and Fairley, and those guys can’t do all the work by themselves.

Detroit’s also lost two-fifths of its offensive line from a year ago. Guard Stephen Peterman was released, while right tackle Gosder Cherilus left for Indianapolis. Remaining starters Jeff Backus is 35 and Dominic Raiola is 34 and slipping fast, and there are questions about whether 2012 first-round pick Riley Reiff will even play right tackle, let alone the left tackle spot he was drafted to eventually occupy.

Those holes from the past few years? Forget about them. The team finally spent big on a cornerback to re-sign Houston, who is capable of playing at an above-average level when he’s 100 percent. After letting the oft-injured Delmas hit the market, they added a second big contract by giving a five-year, $25 million deal to Texans safety Glover Quin, who was an adequate piece on a very good Houston defense. The Lions then moved to stop their seemingly endless rotation of running back prospects by giving Reggie Bush a four-year, $16 million deal to serve as their primary halfback. A Bush–Mikel Leshoure combination would seem to fit together very well, but how effective can they be behind a piecemeal offensive line?

Teams don’t necessarily need to have an identity, but Detroit’s work this offseason evokes images of the captain plugging the holes in his ship while new ones open up. The Lions will likely be better next year — they underperformed their Pythagorean Expectation by 2.5 games — but their moves this offseason are lateral shifts, not improvements.

Safety’s Sake

Defensive backs have been extremely slow to come off the market this offseason, thanks to an incredible supply and extraordinary demands from the players at the top of the class. Even worse, the market’s been further enriched by a series of surprising cuts during the first two days of free agency. On Tuesday, it was Antoine Winfield and Michael Huff; on Wednesday, Bernard Pollard and Kerry Rhodes hit the unemployment line.

That’s why the move by the Buccaneers to give Dashon Goldson a five-year, $41.2 million contract raises eyebrows. Goldson’s an unquestionably talented player who has been chasing this very deal for three offseasons now, only for the 49ers to eventually bring him back on one-year contracts when the market didn’t bear his desired worth. With 2012 first-round pick Mark Barron showing flashes of brilliance in his rookie campaign (and Darrelle Revis reportedly the subject of trade discussions), the Bucs could go from having one of the league’s weakest secondaries to one of its best overnight. After ranking 20th in pass defense DVOA last year, you can understand their desire to try to upgrade with star-level talent very quickly.

In terms of the current market for safeties, though, Goldson’s deal makes no sense at all. The market is almost literally flooded with safeties, none of whom are as good as Goldson, but who are likely to deliver most of Goldson’s production at a fraction of the cost. Could the Bucs have gotten Pollard for three years and $10 million? What about a deal for Ed Reed, Kenny Phillips, Rhodes, Adrian Wilson, or Dawan Landry? Rhodes is 95 percent of the player that Goldson is, and he’s going to sign with somebody for about 15–20 percent of the price the Bucs paid for Goldson.

The issue here, again, is opportunity cost. By committing that much money to Goldson, the Buccaneers are unable to spend money elsewhere. That could cost them Michael Bennett, who was their only viable pass rusher last year and a player at a position without many free-agent options available. It might prevent them from bringing in a more talented right tackle or a slot receiver to play alongside their big downfield threats. The Bucs will rest easy tonight with Goldson in the mix, but they very well might have missed out on an opportunity to make multiple spots on their team better.

Quick Hits

• The multiyear deals for Donnie Avery and LaRon Landry are confounding. Both Avery and Landry were players who had to ask around before getting one-year deals last season, and while they were both contributors, did they really play so well that they deserved multiyear contracts with decent amounts of guaranteed money? Why not hit the market and try to find the next Avery or Landry on a one-year deal for chump change?

• Tennessee gave Shonn Greene $10 million over three years to serve as its big back alongside Chris Johnson. Doesn’t it seem like you should be able to stop spending money on running backs once you give your starter $30 million guaranteed? Greene’s a capable short-yardage runner, but he has absolutely no upside as a starter and can’t possibly do enough work in short yardage to justify this deal. You can see the Titans looking at the Matt Forte–Michael Bush time-share and hoping to emulate that combination in Tennessee, but Bush was a better back than Greene was before taking over that specialized role.

• I love the one-year, $5 million deal the Broncos gave Dominique Rodgers-Cromartie. Buying low on DRC is similar to the move the Broncos pulled with Tracy Porter last year, and while Porter wasn’t able to stay healthy, Rodgers-Cromartie should be able to contribute across from Champ Bailey as a very viable second corner. Other under-the-radar moves that I appreciated: Oakland signing Pat Sims to an undisclosed deal, the Chargers bringing in Chad Rinehart from the Bills to serve as a possible replacement for Louis Vasquez, and San Francisco signing Glenn Dorsey in the hopes of revitalizing the stagnant career of the former fifth overall pick.

• Finally, I’m confused by Arizona’s insistence on signing players who were vaguely associated with Bruce Arians at one point or another. Sure, if they were signing Mike Wallace, that would be a great idea! But bringing in Steelers bust Rashard Mendenhall and Colts backup quarterback Drew Stanton? Yikes. It helps that these players know the offense that Arians will be running, but Mendenhall really hasn’t had a very good career and was putrid during his final season in Pittsburgh, and Stanton’s work in limited time (104-for-187, 55.6 percent completion rate, 6.2 yards per attempt, five touchdowns against nine interceptions) doesn’t scream “I need to start now!” These guys had to learn the Arians system, so what’s so difficult about teaching other players the scheme, too?