COSTA MESA, Calif. -- Gus Bradley has seen it before.
The Los Angeles Chargers defensive coordinator served in the same role with the Seattle Seahawks when the Legion of Boom emerged eight years ago, and he now oversees the creation of another talented secondary.
But while the Seahawks had a unique blend of bravado, size and length, the Chargers have relied more on quickness, playing with precision and anticipation.
"It's really hard to compare this group to that group because each group has its own personality, and that's what drives them," Bradley said. "They're all extremely competitive, and they all want the ball thrown to them -- that part is consistent."
Cornerback Casey Hayward, the quiet ball-hawking leader of the Chargers, eschewed any comparisons to Seattle's dominant secondary, instead laying claim to his group's own identity.
"We're called the Jack Boys," Hayward said. "You know what they call Jack Boys? We try to go in there and be thieves, take the ball away. That's why we're called Jack Boys."
Hayward points to the numbers when asked if the Chargers are among the best defensive backfields in the NFL, and the numbers tell a story.
According to ESPN Stats & Information, over the past two seasons, the Chargers have the best touchdown-to-interception ratio allowed in the NFL (38 TDs, 36 INTs, 1.06 ratio) and have the fifth-best Total QBR allowed (49).
Only the Ravens (40) have more interceptions than the Chargers over the past two years.
"On defense, you want the type of ego that wants the ball thrown at them -- I want to be attacked, throw the ball at me -- but that ego can never take away from the team," Bradley said. "When I was at Seattle, that part was very consistent, and these guys here want that ball thrown at them as well. And it's about the team."
Birth of the Jack Boys
Chargers defensive backs coach Ron Milus admired the Legion of Boom from afar. A Tacoma, Washington, native who played defensive back at the University of Washington, Milus keeps tabs on the team of his childhood.
"One thing I thought they did is play with great technique and a lot of energy," Milus said. "What they put together there in 2010 and 2011 was something special. We are nowhere near that, but we're in a similar defense and we're trying to put together a team that can fight for a championship, just like their team was."
Versatile safety Adrian Phillips said former teammate Adrian McDonald coined the nickname Jack Boys two years ago, when the defensive backs had success taking the ball away during offseason work while the Chargers were still in San Diego.
"We were just in a meeting room and we were trying to find our identity," Phillips said. "That particular offseason was a great offseason as far as taking the ball away from the offense. We were going crazy, and right then and there we found our identity. And A-Mac [McDonald], he brought it to us, and it stuck.
"The thing is, you can't have that name and be out there getting bombed over the top. So that's another thing if you've got that name, just like Seattle had Legion of Boom -- they were the enforcers and the heartbeat of that defense, they had to live up to that. And that's the same thing with the Jack Boys -- we have to be the heartbeat of our defense."
Hayward, a two-time Pro Bowler who earned second-team All-Pro honors last season, leads the way. His 11 interceptions are tied with Marcus Peters for the league lead over the past two seasons.
He plays with a laid-back confidence and likes to let his performance do the talking on the field.
"I'll be honest, last year I thought Casey Hayward was the best cover corner in the NFL, I really believe that," said ESPN NFL analyst Matt Bowen, who played safety for eight NFL seasons. "Hayward, in my opinion, wins with his feet. He has excellent flexibility in his hips, can click and close on the ball."
Hayward is the centerpiece of a close-knit group that includes ascending veteran safety Jahleel Addae, explosive rookie strong safety Derwin James and steady cornerback Trevor Williams, who replaces Pro Bowl cornerback Jason Verrett, done for the season because of an Achilles tendon tear after missing much of last season because of a torn ACL.
Along with those four, the Chargers have a playmaking slot defender entering his second season in Desmond King. Besides the closeness, Bradley said what makes his secondary so effective is its attention to detail.
"They are extremely intelligent," Bradley said. "If you need to make an on-field adjustment, it's done, just tell us what you want. And If you don't see it done, it's probably because you didn't ask them.
"That's what is really unique with this group. You don't have to worry about, 'Oh, we need to get to this, but we haven't practiced it in a week.' Don't worry about it. If they've done it a month ago, you can bring it up -- they have quick recall and they'll go out and execute it."
Pass rush sets the tone
With 78 sacks over the past two seasons, the Chargers are tied for 10th in the NFL.
"We've got some good pass-rushers, so that helps as well," Hayward said. "Just like Seattle, they were built from up front -- they had some guys that could get to the passer and stop the run, and that made it easier on the secondary."
Bradley doesn't have to rely on blitzing to get home, and instead can create consistent pressure with just four rushers, which presents opportunities to get the ball in the back end.
He used a similar blueprint while in Seattle, where the Seahawks are 10th in the NFL in sacks (199) since 2013.
A rookie built like Kam Chancellor
While the Chargers do not have the length at cornerback or a rangy center fielder who can cover the field at free safety like Earl Thomas, they did draft a safety with size, strength and physicality built in the mold of Kam Chancellor in James.
Now, Bradley just has to figure out how to use him.
"He's very talented, with his speed and length, and you saw some plays [Wednesday]," Bradley said. "I think what he's going through right now, when he's in the meeting room and you're asking him questions, he can answer them right now -- he's on it.
"Now, it's coming out on the field and putting it together. So he's in that phase right now. But it's coming, and if he makes a mistake, he knows it right now. So it's just that next step, which you see with some young guys."
For his part, James said his diligent work in the classroom has translated to playing faster and more physical on the field. The rookie from Florida State finished with two tackles -- including a tackle for loss -- in 29 defensive snaps in his first action as a pro against the Arizona Cardinals last week.
James said he looked forward to getting out on the field again to test himself against one of the best quarterbacks in the business in Seattle's Russell Wilson. The Jack Boys host the Seahawks on Saturday.
"I just look forward to playing against everybody, me personally," James said, smiling. "I just love to play ball. ... It's the NFL, so I'm just prepared, trust in what my coaches are teaching me and just keep working hard."
For James and the rest of the Jack Boys, that means continuing to build trust and communicate so they can take the ball away on game day.
"Everybody's doing their one-eleventh," Addae said. "Nobody is out there trying to be Superman -- they're working within the scheme and everybody works within that strength. I just think everyone has bought into Gus' system, his mindset. He asks us to do your job, and if you do your job the plays will come.
"I feel like we're the best secondary in the league, but I feel like we've still got a lot of work to do."