You already know that the defending NFL champions are a unique team. The Seattle Seahawks have a quarterback who is two sizes too small, a running back seemingly powered by candy, and an unconscionably loud home stadium. Something else is strange about the Seahawks, too: how they’re structured. The Seahawks are unquestionably a team built around their dominant secondary under the auspices of Pete Carroll, once and always a defensive backs coach. There are Super Bowl–winning teams from the past with great secondaries — the 2010 Packers come to mind — but the position you associate most with this Seahawks team, more than anything else, is defensive back.

That’s very uncommon. Earl Thomas and Richard Sherman were first-team All-Pros in both 2012 and 2013, attesting to Seattle’s strength in the secondary; the last time two defensive backs from the same team were first-team All-Pros in consecutive seasons, per Pro-Football-Reference.com, was when Herb Adderley and Willie Wood pulled the same feat off for the Green Bay Packers in 1965 and 1966. Kam Chancellor made it to the Pro Bowl in 2011 and 2013, and while the fourth spot in the secondary has been a revolving door, that three-man core has been so good that I started wondering: Do the Seahawks have the best secondary ever?

It’s too early to say for these Seahawks, of course, but in researching the question, I started wondering what the best secondaries in league history looked like and how long they stayed together. The answer to that question, especially in the salary cap era, is not very long. It might take only another couple of seasons at this level of play to declare Seattle the best secondary in league history, and there’s little reason to think that Sherman, Thomas & Co. will slip. And naturally, if it’s not these Seahawks, I wanted to figure out who was in the best secondary in league history, and then the best linebacking corps in NFL history, and then it was four in the morning and Pro-Football-Reference.com actually started playing a MIDI version of “Closing Time” and refused to respond to any more of my searches.

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I eventually came away with a list of the best positional units on one team at any given time in league history. Some are closer than others, and much of it’s a matter of personal opinion, but there’s something more than mere trivia to be gained here. How long does a star unit last, especially in the modern era? How much harder is it to build a particularly incredible group of players at one position than it is at another? And are there any current personnel groupings who could make a reasonable run at the star teams of the past? I’ll try to answer those questions as I go along.

A few quick rules I tried to follow in picking the right candidate(s):

It’s not enough to have a great player on your team if he was well past his prime or wasn’t playing like he had been at his peak. Say the Seahawks traded for Charles Woodson tomorrow and used him as their seventh defensive back this season. Woodson’s résumé is incredible, but as a backup defensive back playing out the end of his career, his actual impact on the team (and its candidacy for best secondary alive) is negligible.

A player’s level of play at the time he was on the team is more important than his past/future level of performance, but both matter. The very good Eagles secondary from the turn of the decade had Al Harris as their nickelback; when he would later get a chance to start in Green Bay, Harris would reveal himself to be a Pro Bowl–caliber player, which helps put his performance in Philadelphia into context, but he’s more valuable to those Packers teams for the purposes of this piece than he is to those Eagles squads.

All press is good press. Having a Hall of Famer in your positional unit is of enormous value. Having two is a surefire way to be in the running. All-Pro and Pro Bowl appearances mean a lot, too. If your group was notable enough to acquire a famous nickname, that helps.

Longevity helps. That 1994 49ers secondary with Deion Sanders was incredible, but Sanders was there for only one season before leaving to join the Cowboys. They might have burned extremely bright while Sanders played by the Bay, but it’s tougher to put that unit over a group like Seattle’s, which has had its three core components together in the starting lineup for three seasons.

It’s harder to do this in the modern game. For a number of reasons, it’s harder to build an incredible positional unit in the current NFL. The salary cap prevents teams from investing heavily at a given position, while the league has grown from 13 teams in 1950 (the earliest point I considered for candidates) to 32 teams here in 2014. I didn’t write off combinations from the past altogether, as you’ll see, but I gave extra credence to succeeding in the modern NFL.

All right. Preamble aside, let’s run through the best positional groupings, spot by spot, since 1950:

Quarterbacks

Winner: Joe Montana and Steve Young, 49ers, 1987-92

A pretty obvious winner here, as Montana and Young were a rare case in which a team had a pair of Hall of Fame quarterbacks on the roster for an extended period of time. Young was hardly an unknown when he was sitting behind Montana, either; he had been a prominent player in the USFL before being taken with the first pick in the USFL Supplemental Draft by the Buccaneers, who promptly gave up on him after two seasons and traded him to the 49ers for second- and fourth-round picks. Montana’s nagging injury issues meant that Young started 10 games during his first four seasons with the team before taking over as the full-time starter after Montana went down with an elbow injury during the 1990 playoffs.

Current Candidate: Peyton Manning and Brock Osweiler, Broncos

There’s no team in football at the moment with two quarterbacks who have any prayer of both winning MVP awards or making the Hall of Fame. The position is just spread too thin, and there’s no team out there with both a very good starter and a first-round pick waiting in the wings. Because of that, I just chose the best quarterback of all time and his backup, who might surprise us all and turn into something. The last real challenger to this throne would have been Brett Favre and Aaron Rodgers when both were on the Packers from 2005 to 2007, but Rodgers threw only 59 passes before Favre left town. They’ll both be Hall of Famers one day and finish a close second to Montana and Young for a long, long time.

Running Backs

Winner: Jim Brown and Bobby Mitchell, Browns, 1958-61

After Brown led the NFL in rushing yards and touchdowns as a rookie in 1957, Cleveland took Mitchell, an Olympic hopeful in track and field, with its seventh-round pick in the 1958 NFL draft. With the bruising 232-pound Brown at fullback and a 192-pound Mitchell at halfback, Cleveland had a perfect big man–small man act. From 1958 through 1961, with Brown and Mitchell at the helm, the Browns ran for 8,768 yards, nearly 1,000 yards more than the second-place Packers, while averaging 4.9 yards per attempt. The partnership ended in 1962, when the Browns dealt Mitchell to Washington as part of a package for the first overall pick, Ernie Davis, who wouldn’t play for a Washington team that had famously refused to sign or trade for black players. Davis would sadly die from leukemia before ever playing an NFL down, as depicted in The Express. Mitchell, instead, became the player who integrated Washington while moving to wide receiver, where he also excelled before becoming a longtime member of the team’s front office.

Brown would also have another Hall of Fame running back as a teammate several years later in Leroy Kelly, but Kelly really made his mark only after Brown retired at the age of 29 in 1966. Their closest competitors are another pair of ’60s running backs: the duo of Paul Hornung and Jim Taylor in Green Bay, who dominated from 1958 to 1966, with a one-year exception for Hornung’s season-long gambling suspension in 1963.

Current Candidate: Adrian Peterson and Jerick McKinnon, Vikings

In 2014, running back is a relative wasteland, so there’s not really a strong one-two punch to compete with the players of yesteryear. In much the same way I chose the Denver quarterbacks, I went with Peterson, a future Hall of Famer, and the young player who might develop into something behind him.

Wide Receivers

Winner: Cris Carter and Randy Moss, Vikings, 1998-2001

Oh, this can head in so many directions, and all of them are going to make a group of fans angry. You could easily justify a half-dozen other combinations as the winners here. Lynn Swann and John Stallworth both made the Hall of Fame. Elroy Hirsch and Tom Fears were a dominant duo in an era when the game was totally different. If you want to expand out beyond a two-person combination, you can point to the Art Monk–Ricky Sanders–Gary Clark trio that powered Washington to Super Bowl wins with different quarterbacks in 1987 and 1991, or the Greatest Show on Turf’s four-wideout set of Isaac Bruce, Torry Holt, Az-Zahir Hakim, and Ricky Proehl.

You can make a reasonable case for any of those teams over any of the others. Carter and Moss stand out, though, for how freakishly dominant they were in their pomp. Carter was already a superstar when this run started, given that he was 33 and coming off of five consecutive Pro Bowl seasons across from Jake Reed. Reed was a good player. Moss was an otherworldly force of nature. Carter slowed down in 2002, but during the four years of this partnership, the duo were first (Moss) and fourth (Carter) in touchdowns by a wide receiver while each finished in the top 10 for receptions and receiving yards. What takes it over the top for me is that they did it with three different quarterbacks; the breakout debut season in 1998 came with Randall Cunningham, who made it to the Pro Bowl without having been an effective starter since 1994. They were almost as great a year later, when Cunningham gave way to Jeff George, with Daunte Culpepper taking over for a multiyear run in 2000. Carter is in the Hall of Fame, and Moss should be in a few years. It’s a narrow victory, and the combination of their names sounds a little too much like a TNT show, but I’m giving this one to Carter and Moss.

Current Candidate: Demaryius Thomas and Wes Welker, Broncos

I don’t know that Thomas and Welker are the best one-two punch in football in terms of talent; you’d almost certainly draft Randall Cobb and Jordy Nelson or Alshon Jeffery and Brandon Marshall over them if you had to pick a duo. In terms of impact, though, Thomas and Welker reign supreme. Welker has an interesting Hall of Great case as quite possibly the best slot receiver of all time and a guy who was wildly productive for six seasons in New England, while Thomas has posted back-to-back 90-plus catch, 1,400-plus yard, 10-plus touchdown seasons with Peyton Manning around. Their role in what might have been the greatest offense in NFL history will not go unnoticed.

Tight Ends

Winner: Rob Gronkowski and Aaron Hernandez, Patriots, 2010-12

Wait, really?

Yes. There’s not a combination of tight ends any better than Gronkowski and Hernandez, who put together a three-year run that feels like ancient history after what’s happened to each of them over the past two years. No tight end duo in history has ever come close to matching their 2011 campaign, when the two Patriots combined for 169 receptions, 2,237 receiving yards, and 24 receiving touchdowns.

Part of this is that the position of tight end is evolving, and the players who suit up there over the next 30 years are unlikely to resemble the often-plodding blockers who suited up there over the previous 30. Even given the stars of the past, there was never a time when a Hall of Famer like Mike Ditka or Kellen Winslow Sr. had a notable second fiddle at tight end for any stretch of time. Gronkowski and Hernandez were the first of their kind and drastically changed the way teams think about building their receiving corps; that helps prove how important their partnership was, even if it didn’t last very long.

Current Candidate: Antonio Gates and Ladarius Green, Chargers

Other teams have emulated the Patriots with limited success; Baltimore, Indianapolis, and Minnesota have all tried to build chunks of their offense around a duo of tight ends. The pair with the highest upside is in San Diego; Antonio Gates is at the end of a Hall of Fame–caliber career, and if you could make the Hall of Fame on a wave of fantasy sleeper articles, Ladarius Green would already have his own wing in Canton. That selection admittedly might look very silly next year.

Offensive Line

Winner: Art Shell, Gene Upshaw, Jim Otto, George Buehler, and Bob Brown, Raiders, 1971

You can spin this one of two different ways. The core of the Raiders team was that Shell-Upshaw-Otto combination on the left side of their line, a group that stayed together from 1968 through 1974. All three of those guys made the Hall of Fame, and the trio combined for 27 Pro Bowls, 17 first-team All-Pro squads, and 45 years of Raiders football. I’d be comfortable picking that trio, but I want to specifically focus on the 1971 team. Buehler was a competent guard, but that season saw Bob Brown — who had made five All-Pro first teams in the previous six seasons — come over to Oakland to play right tackle. He would be a Pro Bowler in 1971 and eventually make the Hall of Fame. Oh, and the swing tackle was Ron Mix, who had made eight Pro Bowls and been a nine-time first-team All-Pro for the Chargers in the ’60s. He, incredibly, was the fifth Hall of Fame offensive lineman on this one Raiders team. There are other great offensive lines — the Hogs in Washington come to mind — but nobody can match this Raiders line for decoration.

Current Candidate: Joe Staley, Mike Iupati, Alex Boone, Anthony Davis, and various centers, 49ers

Boone was the guy who really took this line to the next level when he entered the starting lineup for Adam Snyder in 2012, and ironically, his ongoing holdout may be the event that precipitates its fall from the top of the charts. A mauling group of run-blockers who work perfectly in tandem with methodical veteran Frank Gore, the San Francisco front five are on their third center in five years, having replaced Jonathan Goodwin with backup Daniel Kilgore. If Boone leaves, they’ll struggle to replace his overwhelming athleticism, which might be just enough to push the multitasking unit in Philadelphia into this spot.

Defensive Line

Winner: Carl Eller, Gary Larsen, Alan Page, and Jim Marshall, Vikings, 1967-73

Oh, this one was tough. It was tough enough to toss aside the Richard Dent and Dan Hampton–led lines of the mid-’80s Bears and the Steel Curtain up front on those legendary Pittsburgh Steelers teams of the ’70s. I ended up with two remarkably close candidates, with the Deacon Jones–led Fearsome Foursome of the Rams going up against the Purple People Eaters in Minnesota.

You could, honestly, make a great case for either team. Jones and Merlin Olsen were the leaders of a unit that fundamentally pushed the game of football forward; Jones literally came up with the term “sack” and came to define the archetype of the dominant edge rusher. Eller and Page weren’t as influential, but they might have been more celebrated at their peak; Page was the first non-skill position player to win the AP’s version of NFL MVP and remains one of three to pull off that feat, alongside Lawrence Taylor and KICKER MARK MOSELEY (WHY?). Larsen and Marshall also stayed alongside their two stars longer than any of the variations on the Fearsome Foursome, and in 1969, each of the four men in Minnesota’s defensive line made the Pro Bowl. Even the Fearsome Foursome failed to pull that off. That gave the Vikes a very narrow victory.

Current Candidate: Chris Long, Robert Quinn, Michael Brockers, and Aaron Donald, Rams

Already possessing the best one-two punch at defensive end in football, the Rams used one of their first-round picks this past year on Donald, the best interior pass-rusher in the draft. Carolina had the best line in the league last year, and the Texans are about to combine J.J. Watt and Jadeveon Clowney in their pass rush, but nobody has horses like this.

Linebackers

Winner: Jack Ham and Jack Lambert, Steelers, 1974-82

Pro-Football-Reference.com has a fan rating system that lets readers use an Elo-style head-versus-head system to rank the greatest players in the history of professional football. Lambert and Ham (somehow another TNT show?) are each rated as among the 22 best players in football history at any position. That should tell you a lot. They were so valuable that I didn’t feel the need to pick a third linebacker, but among the starters who lined up alongside them, the best was probably veteran Andy Russell, who made the Pro Bowl in 1974 and 1975. I’ll hear arguments for the 2000 Ravens, the Lawrence Taylor–era Giants, and the Orange Crush, but Ham and Lambert are beyond reproach for me.

Current Candidate: NaVorro Bowman, Patrick Willis, Aldon Smith, and Ahmad Brooks, 49ers

This group looked a lot better one year ago, before Smith went to rehab and Bowman suffered a gruesome knee injury in the playoffs. Carolina has a pretty incredible one-two punch with Luke Kuechly and Thomas Davis, but if this four-man group can get back on track by the end of 2014, nobody in football will be able to touch them.

Defensive Backs

Winner: Dick LeBeau, “Night Train” Lane, Yale Lary, Lions, 1960-64

This was the hardest one to pick, mainly because there really weren’t many secondaries with multiple Hall of Famers who stayed together for five years or more. I thought about the aforementioned 1994 49ers and turned to the early-’80s foursome of Ronnie Lott, Eric Wright, Carlton Williamson, and Dwight Hicks, each of whom made the Pro Bowl in 1984. Lott, though, is the only Hall of Famer from that bunch. The Raiders arguably possessed the best one-two punch at cornerback in league history during the early ’80s, thanks to the combination of Lester Hayes and Michael Haynes, but they were (relatively) weak at safety. The Packers could boast a trio of Hall of Famers in the mid-’60s with Herb Adderley, Willie Wood, and Emlen Tunnell, but Tunnell joined the team at 35 and made only one Pro Bowl as a Packers player.

The Lions, meanwhile, had a five-year run with three Hall of Famers in their secondary. Lane and Lary were among the best defensive backs in NFL history, and while LeBeau’s induction certainly owes something to his impact as a defensive coach, he made three consecutive Pro Bowls between 1964 and 1966. If he ends up as the Chancellor to the others’ Sherman and Thomas, that’s not the worst thing.

Obviously, the current candidates for this honor are in Seattle, and this exercise showed me just how limited the life span of great positional units really can be. It seems like we’re just getting started with the Sherman-Thomas-Chancellor trio, and while this group is signed through 2017, it’s difficult to imagine them playing together for that long. They’re not yet the best secondary in NFL history, but given how effective they’ve been through three seasons together, the Legion of Boom is certainly on its way. More than any other positional grouping in today’s NFL, they have a chance to go down as the best group of players at their position in league history.