NASHVILLE, Tenn. -- For years the safety position has been an afterthought for some NFL franchises when building a defense. Not in Tennessee, where safeties Kevin Byard and Kenny Vaccaro are the focal points of a defense that is tied for the NFL lead in points allowed.

On Sunday, the Titans shut down rookie sensation Saquon Barkley (14 carries for 31 yards) and shut out the Giants after New York had rolled up 70 points in wins against the Bears and Redskins over the previous two weeks.

"You can see when you have that guy in your defense, it's a big deal." Tennessee's Kenny Vaccaro on the importance of the safety position

In an era when offenses are exploding and pass-rushers and cornerbacks typically draw the biggest contracts among defenders, Tennessee is holding teams to 18.1 points per game with a traditional free safety/strong safety combo leading the way.

Free safety Byard was an All-Pro in 2017 with eight interceptions and has three more this season. Strong safety Vaccaro brings a physical presence. Between them they have 118 tackles, four sacks and four interceptions for a team that has played five games against offenses ranked among the top 11 in scoring this season.

Old-school tandem

ESPN analyst Ryan Clark, a former safety, says the Titans are one of the few NFL teams that have an actual free safety and strong safety.

"The marriage of those two guys is an easy one to make based off of where they each excel on the field," he said. "In watching games, Kevin Byard is a ball hawk. He's more of a middle field, rangy, quarterback-read type of player. Kenny Vaccaro is your thumper. A guy you keep closer to the line and a good run-stopper."

Before facing Byard in Week 13, Jets coach Todd Bowles credited Byard for rarely being out of position and consistently generating turnovers.

Former Titans safety Michael Griffin, who coached the Titans safeties during training camp, agrees with Bowles: "It's rare when you see safeties that can do it all," Griffin said. "A guy like Kevin Byard can cover the slot and he is a physical tackler. He does all of the things you wish in a safety. He's a lot like Earl Thomas."

While Byard is the field general in the secondary, Vaccaro is the tone-setter. The physicality he brings shows up when he takes on much bigger offensive linemen in the running game. He loves to deliver big hits on running backs and wide receivers in the screen game as well.

"I think physicality is something you either have or you don't," Vaccaro said. "You can't fake toughness. Some guys are like that, and some guys aren't."

He was signed during training camp after starter Johnathan Cyprien suffered a torn ACL and was placed on injured reserve. Cyprien feels Vaccaro's play gives future opponents an idea of what to expect on game day.

"Kenny is a physical player, and he puts that on tape," Cyprien said. "What you put on tape is a message to the next team you're going to play."

Clark commended Vaccaro for evolving into a well-rounded pro, because coming out of Texas he was known more for his coverage skills than his toughness.

Loaded 2013 class

Vaccaro was the first safety selected in a 2013 draft class stacked at the position. A look at the career path of those safeties demonstrates the volatility in how teams value the position.

As the chart shows, only two of the nine safeties selected in the first three rounds that year remain with the teams that drafted them -- Shawn Williams with the Bengals and Duron Harmon with the Patriots.

"It hasn't played out like everybody wanted," Vaccaro said. "Not a lot of the safeties signed an extension. A lot of guys are on different teams. It's crazy. There are good safeties that came out, but I don't think everybody's story is done. We are all still sticking around. I know I still have a lot of ball to play."

Cyprien and Vaccaro give the Titans two of the safeties from that 2013 class. Cyprien's recovery has him on track to be a part of the offseason program. Now 28, he has two more years on his deal with a $6.75 million salary-cap number each season. Byard still has another year left on his rookie deal before he becomes a free agent in 2020. Vaccaro, 27, who can become a free agent next season, has already proven his value in his first season in Nashville. So General manager Jon Robinson will face a tough decision in the spring, but he would be wise to re-sign Vaccaro.

A big nickel package featuring three safeties wouldn't be a bad idea for Tennessee, especially when they are facing run-heavy teams. The Eagles' defense used a three-safety package that featured defensive backs Malcolm Jenkins, Rodney McLeod, and Corey Graham last season when they won Super Bowl LII.

Safeties often key to great D

There is proof all over the league that safeties are critical to a team's success.

"You can see when you have that guy in your defense, it's a big deal," Vaccaro said. "Keanu Neal, when he went down for Atlanta, that changed their season. [D.J.] Swearinger, he brought a culture to Washington. Tyrann Mathieu, he changed the Texans' culture. You let your pads talk. I am not a 'rah-rah' guy but my film ignites other people. It was undervalued definitely, but I think the value is going to go back up this offseason."

Vaccaro has a point. A lot of the great defensive teams of the past featured a game-changing safety. Clark feels the position has always been important, but acknowledges how safeties are undervalued.

"If you look at great defenses, take the Baltimore Ravens. They moved Rod Woodson to safety, so you had a Hall of Fame guy. When the Ravens were great again, they had Ed Reed patrolling the middle," Clark explained. "Go to Seattle, and they had the Legion of Boom. Richard Sherman was a great corner, but when you look at that defense, it was about safeties Earl Thomas and Kam Chancellor. If you dive into the position, you realize how important it has been historically to great defenses."

The league's growing population of pass-catching tight ends require defenders who can match up against them in coverage, but also fill against the run.

"Safety, other than pass-rusher to me is the most important position on the defense," Clark added. "You're going to be covering [Eagles tight end] Zach Ertz's and [Chiefs tight end] Travis Kelce, but you have to tackle [Cowboys running back] Ezekiel Elliott and [Rams running back] Todd Gurley II, then play the middle of the field against a guy like [Chiefs quarterback] Patrick Mahomes."

Despite the demands of the position, it doesn't always translate into a big payday for the player, possibly because of the inevitable collisions and increased injury risk. Griffin says personnel trends on offense have hurt safeties in the pocketbook.

"I think the biggest thing is it's a pass-happy league," Griffin said. "You don't really have power backs in any more. You look across the league and now you have guys like Christian McCaffrey and Todd Gurley who are pass-catchers/runners. A lot of those safety type of guys are put at a linebacker type of position. You need more athletic type guys, so you have a lot of bigger, more cover type of corners that play the safety position."

The Titans were able to dip into the free-agent market and sign Vaccaro on Aug. 4, and Cyprien was surprised to see how so many safeties were without jobs well into training camp.

"It's crazy, because without the safety back there, things are in chaos," he said. "Safeties are the quarterback of the defense. We have the best view of everything, and we are responsible for putting people in position, making calls. Most importantly we are the last line of defense. It's undervalued in this day and age, especially in this last offseason where it was sad to see so many good safeties sitting at home."

Future of the position

Safeties have provided exciting returns for teams willing to invest a first-round pick in them recently. Safety Derwin James, one of the most talented players in the 2018 draft, was selected No. 17 overall by the Chargers and is a favorite to win the NFL Defensive Rookie of the Year award.

Bowles, a former NFL safety, was surely behind New York using the No. 6 overall pick in the 2017 draft to select former LSU safety Jamal Adams, who has been a stalwart for the Jets.

"If I had 11 Jamal Adamses, I'd be extremely happy," Bowles said. "He's been extremely valuable and is all over the field for us. He studies and has great work habits. To have a guy like that on your team regardless of position, it's invaluable."

Alabama safety Deionte Thompson will likely be a first-round pick in 2019 and have a chance to continue the recent trend of game-changing safeties. Clark believes the success of players such as James, Adams and possibly Thompson will help boost the perception of the position.

"It's showing that talented, good football players can make an impact at that position," Clark said. "I think you're going to start seeing safeties drafted high again. It got to a point where people felt like you didn't need to draft a safety high. Everything works inside the numbers. Teams understand that, and it's now gotten to the point where if you're special at that position you'll get drafted high."