The idea of a base defense being stacked with seven men in the box and four defensive backs is making a brisk march toward extinction.

For evidence of this trend, one needs to look no further a television set on Sunday afternoon. The 3-4 and 4-3 defenses that once populated the NFL during the smash mouth era, back when teams actually drafted running backs in the first round and rewarded those players with second contracts, are no longer the preferred defensive sets for defensive coordinators.

Over the last few years, the preferred base defense for many – if not all of the 32 franchises – has become the nickel defense. In an effort to most effectively match up with the spread offenses and hybrid tight ends that have popped up around the league, many defensive coordinators feel their best chance at survival is to pull a linebacker off the field and replace him with a fifth defensive back.

According to Pro Football Focus, 45 percent of the defensive snaps played across the league last season were out of a nickel package. A dime package (six defensive backs) was deployed on another 12 percent of those plays. The remaining snaps were played out of a base defense.

Locally, the New Orleans Saints used five or more defensive backs on 65 percent of their plays in 2013. During Sunday’s 37-34 overtime loss to the Atlanta Falcons all but two snaps were played out of these packages.

The idea of the 3-4 or 4-3 defense being the base personnel grouping is no longer accurate.

“I think there’s a lot of truth to that, just like the fullback,” Browns head coach Mike Pettine said. “Teams like ourselves, we use a fullback; the Saints use a fullback. It’s a dying breed, has been for a while. … I think nickel defense – I want to say last year for us in Buffalo – was used over 60 percent of the time that we were in some form of nickel where we had at least five defensive backs on the field.

“I think that’s really the defense’s answer. Most coordinators will match speed with speed when you see more and more three-plus receiver groupings, or even two receivers on the field with the tight end like a Jimmy Graham or guys that are the real athletic pass-catching types who you would treat like a wideout in passing situations.”

The issue with playing so much nickel is that it takes a man out of the box, which can make the defense susceptible to the run. While in a subpackage last season, the Saints faced 180 running plays and allowed 5.5 yards per carry. The 3-4 base defense faced 156 runs and held the offense to 4.0 yards per carry.

This could be an issue this week as the Saints come up against Cleveland Browns rookie running back Terrence West, who ran for 100 yards on 16 carries last week against the Cleveland Browns.

For some teams giving up five yards on a run is an acceptable outcome when compared with having to cover a tight end or slot receiver with a linebacker or safety, which leaves the defense vulnerable to a big gain through the air.

And to some degree, the offense is always going to have some type of advantage over a defense that has six or fewer guys in the box, but some minds are not convinced it has to be a crippling one.

“The question is how are you deploying fronts in nickel?” Saints coach Sean Payton said. “You can get in some heavy run fronts in nickel, favorable defending the run and challenging defending the pass. It’s not just defending the nickel. It’s what’s the front and coverage you’re playing within it?”

One other things teams can do is put a third safety on the field in place of a linebacker, which is something the Saints did a lot of last season during Rob Ryan’s first season as defensive coordinator.

This wrinkle to the nickel defense was hailed as something new and exotic when the Saints began rolling it out last season, but it has been around since at least 1992 when Fitz Shurmur was forced to use safeties as linebackers due to injuries in his Arizona Cardinals defense. Shurmur took the wrinkle with him to Green Bay in 1993 and continued to use the package with success.

Known as the “Big Nickel,” many teams, such as the Saints, Chiefs, Patriots and Cardinals, use some variation of it. What’s the advantage?

“You got a guy that can also cover if you need to adjust,” Saints safety Kenny Vaccaro said. “You can also fill in for the run game, too. So, just a ‘Big Nickel,’ really.”

The Saints aren’t afraid to put three safeties on the field. Of the 69 defensive plays it faced the Falcons, New Orleans deployed three safeties 25 times, though that number might have been slightly inflated by injuries suffered during the game. Last year it used three safeties in one capacity or another on 510 plays, or 31 times per game. There were also several other plays when four safeties were on the field.

Still, even though it might help the defense better matchup against spread out offenses, it’s still not perfect against the run, as evidenced in the average yards allowed per carry last season.

“I think the big thing is that you’re getting a guy out of the box,” Saints offensive tackle Zach Strief said. “There’s less guys to block and cover a little more space.”

Sometimes when you’re trying to capture the best of both worlds one half of that equation comes out a little ahead.