Safeties have been the Swiss Army knives of defensive coordinators for a couple of decades now. 

Fast enough to be weapons in coverage, big enough to play near the line of scrimmage, the godfathers of today's box safeties were men like John Lynch, LeRoy Butler, Steve Atwater and Darren Woodson.

But the roles are expanding now. A safety in today's game might be deployed at strongside linebacker, as a nickel back covering slot receivers, a center fielder playing deep or a blitzer off the edge. New Orleans Saints strong safety Kenny Vaccaro played just about all of those roles last season, along with a few more.

NFL teams are looking for more players like him.

"When it comes to safeties in particular, the position has changed where there's more value having a guy in the middle of the field that can do a few different things," NFL Network analyst Bucky Brooks said. "We've seen the league change where people are taking Tyrann Mathieu and some of the other safeties and moving them around as chess pieces on the board."

Valuable chess pieces, given the amount of three- and four-receiver sets that NFL offenses use. Teams spend roughly three-fourths of their time now lined up in a nickel or dime defense, putting a premium on players who can be effective both in coverage and near the line of scrimmage in the running game.

Now, as teams run the ball more and more out of single-back sets, NFL defensive coordinators have started heavily using three-safety packages that involve a center field, free-safety type, a strong safety down in the box and a hybrid who can shift between the two roles. Hit hard by injuries at cornerback and linebacker, New Orleans essentially used a three-safety defense as its base package under Dennis Allen last fall. 

The upcoming NFL draft has more than its fair share of those types of players, led by LSU's Jamal Adams and Ohio State's Malik Hooker at the top and supported by a deep, impressive crop of players behind them.

None are more interesting than Michigan's Jabrill Peppers.

Peppers, a 5-foot-11, 213-pound prospect who ran the 40-yard dash in 4.43 seconds and played linebacker, cornerback, safety, running back and return man in college, has no clear position at the next level. Primarily a linebacker at Michigan, Peppers has branded himself as a safety in the draft process.

The way teams are using safeties now, that might be a good thing.

"Basically they ask me where do I see myself playing, if they were to draft me where would they put me, what are my strong suits, what are my weaknesses," Peppers said. "I tell them my natural position is definitely in the defensive backfield. I had to fill a void this year because it was best for the team, and if I had to do it all over again I would."

Peppers has been the most high-profile safety in the draft who can do a variety of things for a defense.

But he's far from the only one.

Budda Baker, who was the heart and soul of the Washington defense last year, is the other brand of Swiss Army knife, a capable coverage man who has some cornerback skills in addition to his ability to play near the line.

"Teams like my film, whether it's free safety, strong safety, nickel," Baker said. "They feel like I can rush off the edge, play man, make open-field tackles. I feel like I'm equally proficient in all those types of things."

Intelligence is also more important than ever at the position.

When a player is asked to handle so many roles, he has to have an encyclopedic knowledge of the defense, almost like a middle linebacker.

"I’m very versatile, I can play both safety spots," Florida's Marcus Maye said. "I’m one of the leaders in our secondary, and I take pride in being one of those guys who gets other guys lined up. I can make plays anywhere, in the box or deep in the middle of the field. Anything they need from me, I’ll be that player."

Whatever the designation, teams are looking for difference-makers.

Instead of finding a prototype, teams often find a safety who has a nose for the football, then tailor his role in the defense to him.

"(There are) a lot of unknowns, I don’t know what all of those things are," Peppers said at the combine. "But the bottom line is I’m a ballplayer, and I’m a hell of a ballplayer."

Follow Joel A. Erickson on Twitter, @JoelAErickson.