It's no wonder the odds-makers put the Steelers as 3-point favorites over the Ravens, the exact amount of points traditionally given to home teams. They appear to be identical teams in so many ways.
We can see why in the graph below. Like I did recently with running and passing Success Rate (SR) charts, I've plotted each team's total offense and total defense. This time I used opponent-adjusted SR, which accounts for the SRs of each team's opponents.
Unlike passing and running SR, which correlate to a fair degree, there is no reason to expect team offense and team defense to correlate. We shouldn't expect to see a nice tight diagonal relationship like we did when looking at passing and running. But we can still see team balance.
The graph below plots team defensive SR by team offensive SR. The vertical axis is defense, and the horizontal axis is offense. The red lines indicate the league averages. Teams along the diagonal running from the bottom left to the top right are balanced between offensive success and defensive success. Teams far from that diagonal are unbalanced. In the upper left we'd find teams with good defenses but poor offenses, and in the bottom right, we'd find teams with good offenses but poor defenses.
Keep in mind SR is not everything. Some offenses are "big play" offenses, and both PIT and BLT qualify. Roethlisberger and Flacco throw deep on greater than 24% of their attempts. They are built by design not to have very high SRs. And as I mentioned yesterday, NE's defense might be the reverse--designed to allow lots of short successes while rarely giving up the big play.