7: Number of passes from Pittsburgh on second-and-1.

Only five teams in the NFL have more passes than runs on second-and-1: Pittsburgh, Dallas, New Orleans, Minnesota and Tampa Bay. The down-and-distance represents a unique opportunity for offenses to maximize upside without much risk, yet most teams take the “sure thing” and run on second-and-1 at nearly a 70 percent clip.

On his second-and-1 passes, Roethlisberger has three touchdowns and a 140.5 passer rating. He connected with Mike Wallace on a 40-yard touchdown just last week that came on second-and-1.

17.2: Percentage of Roethlisberger’s passes that utilize play-action.

You’d think the Steelers would use more play-action than they do; even though their rate is nearly twice that in Dallas, it still ranks only 20th in the NFL. Roethlisberger has a 71.0 completion percentage and 104.9 passer rating on play-action looks in 2012.

10.6: Percentage of Roethlisberger’s passes that travel at least 20 yards.

When you think of the Steelers’ receivers, you think of speed. Wallace joins Emmanuel Sanders and Antonio Brown as three of the fastest players in the entire NFL, regardless of position. Because of that, defenses tend to be cautious with the trio, playing off so as to not surrender big plays. There’s evidence of that in the Steelers’ wide receiver screen usage, which leads the league, and Roethlisberger’s deep-ball rate, which ranks him only 26th in the NFL.

The Steelers have been relatively unable to capitalize on their deep looks, too. Roethlisberger has actually completed fewer than half as many deep passes as Mark Sanchez. Wallace, Sanders and Brown rank 18th, 38th and 46th in the league in deep-ball rate. Nonetheless, I think the lack of big plays downfield is more telling of how defenses play the Steelers than any problem inherent to their offense.

Defense

5.1: Net-YPA allowed by Steelers’ pass defense.

So how have the Steelers kept themselves alive for yet another playoff berth despite an offense that has been mediocre up until this point? Like usual, it’s the defense. The Steelers have the league’s second-most efficient passing defense, due in large part to their secondary.

91: Targets at cornerback Keenan Lewis.

Only two cornerbacks in the NFL have been targeted more than Lewis, but the big, physical defensive back has excelled this year. Lewis has allowed only 5.62 YPA and a 74.9 passer rating in 2012. With cornerback Ike Taylor out, Cortez Allen has also been thrust into the starting lineup. The 5.84 YPA and 80.0 passer rating he’s yielded are right on par with Lewis.

If there’s a weak spot in Pittsburgh’s secondary, it’s nickel corner Curtis Brown. In limited action, Brown has allowed a 75.0 completion percentage, 9.67 YPA, and a passer rating of 132.6. Look for the Cowboys to utilize three-receiver sets, whether they want to run or pass, to get Brown on the field.

7: Defensive interceptions.

The only knock on Pittsburgh’s secondary is that they haven’t been able to force turnovers; their seven interceptions rank them 31st in the NFL, ahead of only Dallas. Like the ’Boys, the Steelers haven’t gotten the same amount of pressure they’re accustomed to generating. As I’ve shown in the past, pressure is strongly correlated with takeaways, so the interceptions will come for both teams as the pass-rush improves.

To recognize just how poorly the Steelers’ rush has been in 2012, consider that their 6.0 percent sack rate ranks just 18th in the league and they’ve pressured the quarterback fewer than three-quarters as many times as Dallas.