SEATTLE -- There was always a plan. To the rest of the league, it was obnoxious: four defensive backs strutting, dancing and flapping their gums in a faraway corner forgotten by football. "I love you, Bro," they'd say to each other during warm-ups. And opponents hated playing them.

But this is just the way Richard Sherman choreographed it. He'd sit up at night, going over his material like a comedian about to take the stage. I've seen better hands on a snake. You're a bunch of bad routes and talk.

Sherman, a fifth-round draft pick of the Seattle Seahawks in 2011, was doing this before he had any clout in the NFL. Now in most NFL cities, this wouldn't fly. But Sherman's coach is Pete Carroll, a free thinker who allows his men to be who they want to be, just as long as their creativity doesn't hurt the team. But by the midway point of the 2012 season, after Sherman taunted New England quarterback Tom Brady and started calling himself Optimus Prime, even Carroll was wondering what was up.

So Carroll summoned Sherman to his office. Carroll didn't yell; he just wanted to know where Sherman was going with all of this.

Sherman turned serious. He told Carroll that he wanted to be a Hall of Famer, wanted people to call the Seahawks' defensive backs the best in the league. Sherman said he knew they were the best, but they had to get noticed, and he didn't want to wait.

"Cool," Carroll said. "Go for it."

It is the last Monday of 2013. The Seahawks are the No. 1 seed in the NFC and are enjoying the bye week, and Kam Chancellor is scrambling to get a massage, but first he must discuss the origins of the "Legion of Boom," the nickname for a group of castoff defensive backs who have captured the heart of Seattle.

Every great defense has a nickname, right? The Steel Curtain, the Monsters of the Midway … Only the Seahawks, never short on words, couldn't quite come up with anything on this rare occasion. "The Four Horsemen" was suggested, but no, that had been done and was sort of exclusionary. "There's more than four of us," Sherman said.

Chancellor was on a radio show when he was asked about what type of player he was, and the walloping 6-foot-3, 232-pound safety said he liked to bring the boom. Shortly after that, a fan offered up the "Legion of Boom" nickname via Twitter. T-shirts were printed. Floormats, bumper stickers and legends were made.

None of the promotion seemed over the top. The secondary is Seattle's identity, and it is punishing, loud and yet somehow playful. It is intimidating, helping collect a league-high 28 interceptions and a wide array of bruised bodies and egos. It can be maddening, watching Sherman and his buddies flying around, gesturing wildly, congratulating each other like high school boys after every big play.

"They're very, very connected," Carroll said. "I think they illustrate and demonstrate the spirit of this team probably as well as any group."

The Seahawks had the No. 1 defense and top passing defense in the NFL in 2013. They allowed just 172 passing yards a game, and quarterbacks mustered just a 63.4 passer rating.

They've done it with one of the youngest secondaries in the league -- none of the current starters is older than 25 -- and with a collection of players who were considered near the bottom of the scrap heap, mainly fifth- and sixth-rounders deemed either too big, too small or just not the right fit.

Carroll, who got his start coaching defensive backs nearly four decades ago, took an unconventional approach. He put big, athletic bodies in spots that were normally occupied by the small and swift.

He built a secondary with a chip on its shoulder the size of Mount Rainier.

"These guys come from diverse backgrounds," Carroll said. "They come from L.A. to Texas to the hills of Virginia. I mean, they're as spread out as you can get. But I think it's the cause that brings them together. They have joined in to be great. And they're going to do whatever it takes, and part of that is helping each other be at their best."

Cornerback Richard Sherman might be the most vocal member of the Seattle secondary. Steven Bisig/USA TODAY Sports

There is just one true requirement to play in the Seahawks secondary, according to Carroll. A guy has to know how to catch the ball. Confidence is paramount, too, because Carroll oozes it.

The day before the regular-season finale against the St. Louis Rams last month -- a game that would clinch the Seahawks' NFC West title -- Carroll brought in Bill Russell to speak to the team.

"He was like, the night before the playoffs, everyone would ask him, 'Are you nervous?'" cornerback Byron Maxwell said, recalling the speech from Russell. "And he's like, 'No. I'm not playing Bill Russell and the Celtics.' So it's kind of like that mindset. They've got to deal with us.

"It's not cocky. It's confidence."

Each Legion of Boom member has a role. Chancellor is the enforcer. He is built like a linebacker. His hits are so ferocious that, according to a Twitter feed from former Arizona Cardinals safety Hamza Abdullah that made the rounds locally, Chancellor once leveled a tight end so hard that Abdullah saw the kid's soul "leave Qwest Field right on that 35 yard line."

Sherman is the brains behind the operation. He's also long and athletic and can catch nearly anything, leading the NFL with eight interceptions in 2013. Earl Thomas is probably the ringleader, the one who's the only first-round draft pick of the bunch (2010), the one who's always in the middle of the pile, who treats every day as if it's his last game. Thomas is the smallest player in the secondary at 5-foot-10. But the free safety's mere presence prevents big plays. "Think about how many times over the last couple of years you've seen a post route," Carroll said, "which is one of the most common routes in football, thrown at our defense for a big play. It doesn't happen very often. I can barely remember any of them."

Sherman returns an interception for a touchdown as coach Pete Carroll, right, cheers from the sideline during the fourth quarter against Houston earlier this season. Seattle won 23-20 in overtime. AP Photo/Patric Schneider

And then there's Maxwell, a quiet cornerback who was a sixth-round pick out of Clemson in 2011. Maxwell has had four interceptions in the past four games.

Sherman pauses when asked about Maxwell's role. "I'm trying to think of the perfect analogy," he said. "He's the new kid on the block."

Maxwell has taken the place of Walter Thurmond, who was suspended four games for violating the league's substance-abuse policy.

Thurmond is back, but it was Maxwell who started the season finale against the Rams. They're playing because a charter member of the L.O.B., Brandon Browner, is gone, suspended indefinitely for also violating the NFL's substance-abuse policy. Browner had arguably the best story of the group. He was undrafted, had a short stint with the Broncos, then spent the next four years in the Canadian Football League before Carroll brought him to Seattle. After his first full season in the NFL in 2011, Browner went to the Pro Bowl.

Though Maxwell has fit in perfectly, something isn't right.. They miss Browner. He's been underground since leaving the Seahawks, occasionally posting on his Twitter account, and when he does type something, it's usually a supportive note for his teammates At the top of his page, it says, "Tough Times Don't Last, Tough People Do."

They're a brotherhood. That's the word used most frequently among the secondary. They exchange "I love you's" before each game, unconcerned with how it might sound, because they know it could be the last time they play together.

"I think the biggest key is that the affection the whole group has for each other is genuine," Chancellor said. "There's nothing fake about it at all. We know our brother has our back. If that's the mindset everyone has, we know as a unit we'll be powerful." They vacation together in Miami and take an annual trip to Lake Chelan in Eastern Washington, snorkeling, sitting on a boat, clearing their heads. The entire secondary -- plus a good chunk of the entire team -- went to a Drake concert together recently. The group inclusion is what some believe help the backups seamlessly fit in.

Sherman first met Thomas and Chancellor during the 2011 lockout. They went to an L.A. Fitness to play a game of basketball against some of NBA guard Jamal Crawford's crew. Sherman had never talked to his new teammates before that, but he was struck by how well they played defense together that day.

"We just had a good chemistry out there," he said.

Byron Maxwell has made the most of his opportunity to start. Jim O'Connor/USA TODAY Sports

It didn't start out as a lovefest. In those first days together in 2011, the defensive backs, Sherman said, "were a bunch of individuals."

Thomas was the only one with starting experience, and he almost got benched his rookie season in 2010. He was too unpredictable. Maybe his chip was too heavy. The All-American from Texas, desperately trying to prove himself, thought he needed to make big plays. His coaches just wanted him to concentrate on playing the defense they were calling.

"He used to jump all around and chase everything like his head was cut off at times," Carroll said. "He wanted to do the right thing. He just had a young man's perception of it."

Chancellor played the 2010 season behind veteran Lawyer Milloy. Unlike Thomas, Chancellor had spent the better part of his life unnoticed. His name was spelled wrong by recruiting experts. He went to Virginia Tech as a quarterback, but changed positions twice before he found his home at safety. He waited until the 133rd pick to be selected by Seattle in 2010.

But in Chancellor's first month as a starter in 2011, he was no longer anonymous. The Seahawks were playing Arizona. Chancellor delivered a punishing block that sent tight end Todd Heap flying. Chancellor was flagged, and both teams started jawing. The Legion of Boom was taking shape. Fueled by perceived slights, buoyed by a newfound friendship, the secondary took off. Chancellor, Thomas and Browner wound up on the Pro Bowl roster, and they brought Sherman along to Hawaii to share in their moment.

"I embrace that I was drafted in the fifth round," Chancellor said. "I think it was a blessing. It happened for a reason. I'm out here in Seattle doing what I do, doing what I love to do and getting paid for it."

Former Seahawks cornerback Shawn Springs said their fun is evident, and this secondary reminds him of the great Washington Redskins defensive backfields he played on in the 2000s with LaRon Landry, Carlos Rogers and the late Sean Taylor.

"We used to have a competition amongst ourselves because we all felt like we were the best," Springs said. "And I have to feel like those guys feel the same way. Nobody wants to be the weak link. You feed off that energy.

"It's exciting to see the Seahawks' success run through those guys. It's amazing to see how those guys have really transformed that city."

Kam Chancellor's role in the secondary: The enforcer. Joe Nicholson/USA TODAY Sports

In 2011, when it became clear to Sherman that he was being snubbed in the draft, he made a promise to himself. If he had to be a late-rounder, if he had to make less money and play with fewer guarantees, he was going to do things his way, talking and walking with swagger.

"And if they're going to cut me," Sherman told himself at the time, "and not let me play the game like this, then that's just how it's going to be."