Prior to this season, the prevailing thought was that the Pittsburgh Steelers were the mountain that Joe Flacco had yet to conquer.
That has obviously changed after the quarterback led the Ravens to their first regular-season sweep of the Steelers since 2006. But maybe the focus should have been on a different AFC North rival.
Cincinnati Bengals — the Ravens' opponent this Sunday — Flacco has endured some of the poorest outings in his career. Perhaps not coincidentally, the Ravens are 1-3 in their last four contests with the Bengals.
"They are a physical football team," Flacco acknowledged. "Like I said, they have played well. Their offensive line, their defensive line, they are two pretty good groups. They'll fight 60 minutes, and they fight to the whistle hard on each play."
One factor in Flacco's struggles against Cincinnati has been the defense's use of the cover-2.
In this scheme, the cornerbacks run with the receivers, but hand them off to two safeties, who split the field and have deep coverage responsibilities. In a 4-3 defensive front like the one the Bengals play, the middle linebacker drops back into coverage to shadow a tight end or a receiver running an underneath route.
The alignment is designed to eliminate big plays and places an emphasis on speed and pursuit. And statistically, the scheme has flustered Flacco.
Against Cincinnati, Flacco is averaging 178.2 passing yards and has tossed nine interceptions against just four touchdowns. The average yards and total interceptions are the worst Flacco has registered against an AFC North opponent in his career.
Flacco has thrown for more than 200 yards in just one meeting with the Bengals, but NFL Network analyst Joe Theismann said the past should not be held against Flacco with regard to Sunday's game.
"If we take a look at some of the struggles that Joe has had against Cincinnati, I think a lot of it is, he's had a limited place to go with the football," the former Washington Redskins quarterback said. "If you just take a look at the pieces that have been added in the last two years — two new tight ends, speed on the outside — you've basically changed four of the five receiving positions outside of the running back in a year-and-a-half. Now is when you have to look and see the progress that Joe can make because there are no excuses.
"It isn't that you don't have speed to stretch the field," Theismann continued. "It isn't that you don't have athletic, young tight ends to go make plays for you. It isn't that you don't have a beastly slot receiver. Anquan Boldin is to the Baltimore Ravens what Wes Welker is to the New England Patriots. He's an unstoppable slot receiver. You're absolutely right in asking what was Joe doing before. Cincinnati has always played pretty darn good defense, and they're really good this year again."
Cincinnati's strategy has been headed by Marvin Lewis, the defensive architect of one of the best units in NFL history that captured the franchise's first Super Bowl title in 2000.
Lewis chuckled at a question probing his defense's success against Flacco and declined to reveal any secrets.
"I don't know," he said. "I think you defend a team's offense each and every week. That's part of what your charge is on the other side. I don't know if we've done anything that special. I think we're 3-3 against Joe. So that, I wouldn't say, is as special as you want it to be."
The Bengals have surrendered just one 300-yard passing game this season (323 yards to the Seattle Seahawks' Tarvaris Jackson in a 34-12 loss on Oct. 30) courtesy of a pass rush generated by the defensive line. That unit has accounted for 20 of the team's 25 sacks and takes some of the pressure off of the defensive backfield, according to former Ravens coach Brian Billick.
"[T]o be able to do that with a four or five man rush gives you a lot of latitude," the analyst for Fox Sports and the NFL Network said. "It leaves you less vulnerable in the secondary. That's the combination I see in Cincinnati right now. It's not a lot different frankly than what we did when we made our Super Bowl run. We got to be known as a team that brought pressure. Well, we did. But we did it with four or five-man fronts. Like I said, I don't think it's just Joe Flacco. I think Cincinnati has shown that they can give a lot of quarterbacks issues, and it's mainly because they can put some pressure on you with just a four or five-man front and play some zone packages behind you."
The challenge for the Bengals this Sunday is playing without cornerback Leon Hall, a solid defender in the cover-2 system. The absence of Hall, who tore his left Achilles tendon in last Sunday's loss to the Pittsburgh Steelers, and Johnathan Joseph, who left to join the Houston Texans via free agency in the offseason, means that Flacco and the Ravens will see two different cornerbacks in Nate Clements and either Kelly Jennings or Adam "Pacman" Jones.
That should play into the Ravens' favor, according to CBS Sports NFL analyst Dan Dierdorf.