For the better part of the past five years or so, the NFL has been trending toward becoming what many refer to as a “passing” league.

Rule changes, spread offenses and increased athleticism have led to record-shattering air attacks all over the league.

Meanwhile, in the NFC West, there has been a slow boil taking place, a boil that has little to do with flashy passing games and a boil with a decidedly old school feel to it.

Stout, hard nosed defenses and power running games are the order of the day amidst the high-wire acts taking place around the league.

“It’s the MFL, I mean, it’s the ‘Manly Football League,’” Rams assistant head coach Dave McGinnis said. “That’s what it is and that’s the way it’s going to be and of course, this division is pretty interesting as far as the way that it’s evolving. It’s starting to remind me a whole lot of that first division I was in, in Chicago where you buckle up, you take two chin straps and two mouth pieces to the ball game, and then you go. This is going to be a huge, huge test for us.”

The Rams begin their first tour through the newest edition of the “Black and Blue Division” on Sunday when they host a Seattle team that is openly embracing the NFC West blueprint at the Edward Jones Dome.

Sunday’s matchup with the hated Seahawks is the first of what should be a bruising week for the Rams as they play Arizona, a team cut from a similar cloth as Seattle only four days later.

San Francisco, the reigning division champion and the team that seemed to perfect the new blueprint the quickest awaits in the Rams’ first game after the bye.

“I think our division will, at the end of the season, have four of the top defenses in the NFL,” running back Steven Jackson said. “All are very aggressive, all have a lot of athletes on that side of the ball and a lot of them create turnovers. We, as an offense, are going to face some tough defenses not only in practice, but six games at least out of the year where each and every game is probably going to come down to the fourth quarter.”

To anticipate a series of slugfests is probably the best way to approach the six NFC West games.

Three games into the season, the three other teams in the division are sitting in lofty company in terms of defensive rankings. To wit:

San Francisco is 11th in total defense (321.3 yards per game), eighth in rush defense (91 yards per game) and 12th in scoring defense (21.7 points per game allowed).

Arizona is 10th in total defense (316 yards per game), ninth in passing defense (210 yards per game) and second in scoring defense (13.3 points per game allowed).

This week’s opponent, Seattle is the best of the lot, sitting fourth in total defense (272.3 yards per game), 10th in pass defense (210 yards per game), second in rush defense (58.7 yards per game) and first in scoring defense (13 points per game allowed).

The Seahawks are also sixth in the league in rushing with an offense centered on powerful back Marshawn Lynch. The shift to physical and powerful has actually been coming since last season when the Niners took off using it and Arizona and Seattle closed the season with a flourish.

The Rams, seeing the trend that was forming, hired Jeff Fisher to bring a similar mentality and he’s been an ideal fit thus far.

“Yeah, there was no doubt about it,” Fisher said. “You could see it coming together and obviously, it came together for the 49ers last year. There’s a great deal of talent in this division. It’s going to be a challenge for us.”

Maybe the formula seems unconventional in today’s NFL but it’s been effective and reliable in the first three weeks.

Heading in to week 4, the NFC West has more combined wins than any division in the league with eight. NFC West teams have traveled outside of the division to do their damage as well, owning wins against the likes of New England, Philadelphia, Green Bay, Dallas, Washington and Detroit.

So, why the seismic change and vastly different approach than the other teams in the league? McGinnis points to a group of throwback head coaches with long histories in the NFL. Seattle’s Pete Carroll, Fisher and Ken Whisenhunt grew up in systems that placed a premium on running the ball and playing strong defense.

San Francisco coach Jim Harbaugh played quarterback in an era where the run game and stout defenses were the norm.

“There’s very good coaches in this division,” McGinnis said. “There’s very good coaches in the National Football League, but you can see kind of the physical mentality of where this division is going. That’s what it is and that’s good because that’s the way we’ve always coached football in this league, and I’m talking about Jeff Fisher and his football teams. Physical is where you start.”

And physical figures to be the word of the day when the Seahawks and Rams square off on Sunday.

Seattle is coming with a defense riding as high as any in the league after it sacked Green Bay quarterback Aaron Rodgers eight times on Monday night and catapulted the Seahawks to a surprising, yet controversial, victory.

The Rams have an offensive line still learning to work together and must find ways to not only protect quarterback Sam Bradford but create some holes in the running game.

That might be easier said than done but Rams offensive coordinator Brian Schottenheimer said the key to slowing down any dynamic pass rush is to keep it out of obvious pass rush situations.

“We knew that each week’s going to be a challenge,” Schottenheimer said. “I think that we, against these guys, we have to play well. We have to execute. The big thing for us, I think, is that we need to stay on track. On first down, we need to stay on track. These guys are really, really good when you get into third-down and long situations. Again, I think, last week we just didn’t play very well. Chicago, I give them a lot of credit, we didn’t play very well. The week before, we did. So, we’re just excited about getting back on track. It’s a great challenge. Again, you talk about top two or three in most rankings and again, I’m glad we’re playing them at home.”

On the other side, it’s probably safe for the Rams to expect a steady diet of Lynch coming downhill right at them. Rookie defensive tackle Michael Brockers is expected to return from an ankle injury which could bolster the team’s run defense.

Aside from Lynch, the Seahawks have rookie quarterback Russell Wilson handling the snaps. Wilson is a bit small but plays much bigger with plenty of poise. The Rams will look to bait him into some mistakes and take advantage by coming up with turnovers.

“The first thing that I see from him is a lot of composure,” McGinnis said. “He’s a guy that is very sure of himself out there. They’re doing a very good job with him. Of course it benefits him greatly, as it does any young quarterback in this league, to have a real horse to be able to hand it off to, that you can lean on that. But he’s a very composed guy. They like to move him. He can get on the edges. He’s extremely athletic and he’s accurate when he takes off and throws it.”

Don’t expect to see a lot of flashing lights on the scoreboard on Sunday. The Rams defense has been moving in the right direction in its own right and will be challenged with the task of keeping the Rams in it.

In what figures to be the first of about six 12-round heavyweight fights for the Rams, the team that can land the one or two big blows will likely come out victorious.

“You know, obviously, I think everybody talked about San Francisco, but you heard the rumblings,” Schottenheimer said. “Again, a lot of respect for Coach Carroll, obviously, what Arizona is doing, and again, I think, our defense is well on their way as well. So, I think, it’s setting up to be a great division. We’re excited about the challenge this week and again, we’ll find out a lot about our guys and I think that they’re excited to have an opportunity to play the game coming off a disappointing performance last week.”