Breaking down the evolution of the Steelers

The Pittsburgh Steelers are a team we have become very familiar with over the years. Once upon a time, our teams were virtually mirror images of each other minus a sizeable Pittsburgh quarterback advantage from 2004-2007. Both teams featured highly talented defenses that perennially ranked in the upper echelons of the league.

Here are each team's respective defensive rankings (by DVOA, not yardage, as always):

source: Football Outsiders

That is a really long run of sustained greatness on defense for both. Pittsburgh's worst year until recently was 2003 which set them up with the 11th pick in the 2004 draft. That worked out well for them. In their three Super Bowl appearances, they had the #1 defense twice by DVOA. However, from 2010 on, the Pittsburgh Steelers would evolve noticeably.

Pittsburgh is an offensive team and has been since 2012

Long gone is the suffocating defense that we are accustomed to. In its place is an offense operating at a high level (currently fourth in the NFL) that has been the driver of their 5-3 record.

They are without a doubt an offensive team and this has been the case for several years now. While I will leave to their fans the hypothesizing about whether Pittsburgh's defensive problems are simply talent deficiency or an issue with Dick LeBeau (there is evidence to suggest both), I will note that their defense has been in steady and clear decline since 2010:  from first, to seventh, to 13th, to 19th to now 26th through eight games.  That is what we would call an obvious downward trend.

Of course, there's no reason why the Steelers can't put on a good defensive performance on Sunday and I'll be the first to suggest that trends only go so far with these teams. They know each other too well. The Ravens offense has been pretty good this year but it's had enough head-scratching outings to cause some doubt as to which offense will show up anyway, especially with Daniels and Forsett banged up and Pitta on IR.

Baltimore has rarely scored many points against Pittsburgh anyway. Even the 35-7 game from 2011 came on the back of a +7 turnover margin. I wouldn't expect Baltimore to have a huge outing this time either but it needs an above average one if it wants to win.

The ever-important turnover margin

Speaking of turnovers, it is a statement of the obvious to say that the game (or any game) will probably hinge on who wins that battle but there is at least some interesting data to point out.

After all, from 2008 until the AFC Divisional game in the 2010 season, Pittsburgh never lost that battle and won six of eight games in that span. From 2011 onward, Baltimore never lost the turnover battle against Pittsburgh and won five of seven games in that time. In games where the turnover margin was zero, Baltimore won only one of the four games but all of them were by four point margins or less.

The turnover margin will undoubtedly be a major factor in deciding the victor but turnovers have an element of randomness to them also. There's more going on here than stating their obvious importance.

Verdict: Baltimore's offense must exploit Pittsburgh's defense to win

In the NFL, each game and each week largely exists in a vacuum. "Momentum" and other such qualitative arguments are convenient responses to whatever the most recent game outcome was but always fail to find foundation in reality. They are some of the laziest arguments you'll ever see but they are par for the course in sports where narrative trumps accuracy.

Maybe the Steelers feel confident after a 51-point outing and maybe the Ravens are fired up and angry about letting the Bengals escape.

Whatever.

Let's focus on what is knowable. We have plenty of data to tell us about each team thus far. The key, as always, is in the execution. This is why we play the games — because if momentum and emotions mattered that much, the season could be decided after one week. It still takes 21.

Pittsburgh's multi-year evolution into an offensive team has brought the spotlight onto players like Brown, Bell and Roethlisberger after years of spotlighting the defensive players. The Steelers will score some points but Baltimore, even without Jimmy Smith, has enough talent to keep it from getting out of hand.

Pittsburgh's defense against Baltimore's offense feels like the real key to this game. The advanced metrics tell us that the Ravens offense is good enough to move the ball and score while Pittsburgh's defense is vulnerable. However, trends only tell us what will probably happen, not what will happen.

Winning in the NFL is often a product of successfully exploiting your opponent's weaknesses, and for Pittsburgh, that is their defense after years of being their identity. Baltimore must capitalize as they cannot hope to keep the high-performing Steelers offense to a 13-9 type of game as they once did when both teams trotted out top five defenses to wage modern day trench warfare.