Is Bengals’ pass defense reason for concern?

Quick question – What do Darwin’s "Missing Link", Amelia Earhart, the Ark of the Covenant, and the Bengals' pass defense all have in common? Answer: They are all missing.

Over the last three weeks the Bengals are giving up 330 passing yards per game, and giving up a quarterback rating of nearly 100 to opposing quarterbacks.

And it’s not as if the Bengals have faced Tom Brady or Aaron Rodgers during this stretch. Rather it’s been the likes of Alex Smith and Joe Flacco who have been torching them through the air. The same Alex Smith who has a career average under 200 yards passing per game, and the same Joe Flacco who opened the year with a 38.2 quarterback rating after Week 1.

Marvin Lewis acknowledged the defensive sieve in the Bengals-Chiefs post-game press conference. "Defensively we gave up some chunk type plays. We need to do a better job there, but we played well in the red zone and kept them from scoring touchdowns," Lewis said.

When asked if he was concerned with the yardage given up, he said, "You want to play better, but you have to stop them on third down and that prevents yardage. We had some third downs that we allowed them to convert, and we have to do a better job of that."

So let’s look at how the Bengals have done defensively after four weeks.

Week 1 Oakland

In Week 1 the Bengals faced Derek Carr, at least for a little while. An injury forced Carr out of the game and his replacement was Oakland’s backup quarterback Matt McGloin. Since this was an "in-game" injury, McGloin had little time to prepare for the starting role with minimal rep’s in practice leading up to week 1.

Much of McGloin’s work was in "garbage time", with the Bengals holding a big lead. But this aside, it was still a second string quarterback with little preparation time. The Bengals gave up a 74.2 percent completion rate and two touchdowns to Oakland’s backup quarterback.

Week 2 San Diego

Philip Rivers’ game is most remembered for Vincent Rey’s game winning interception. But for the first 59 minutes of the contest, Rivers feasted on the Bengals’ secondary.

Rivers completed 77.8 percent of his passes for 241 yards. He also scored a pair of passing touchdowns. His quarterback rating was a very impressive 113.1 for the game.

Week 3 Baltimore

Joe Flacco aired it out a whopping 49 times at home against the Bengals. And it wasn’t because the Ravens were down by a huge margin, but rather, it was because the passing game was working. And when your secondary allows a 36-year-old receiver to record the second most catches, third most yards, and third most touchdowns of his 200+ game career, your opponent’s passing game is clearly working.

Flacco completed 65.3 percent of his passes for 362 yards with a pair of touchdowns and one interception. As a result, he scored a solid 92.4 quarterback rating on the afternoon.

It was Flacco’s best performance of the year with his highest total of passing yards, most TD’s, fewest INT’s, best completion percentage, and best quarterback rating so far this season.

Week 4 Kansas City

Kansas City had to settle for an unlikely seven field goals. And while the Chiefs may have struggled putting the ball into the end zone, they had little problem moving the ball and getting close to the end zone.

Alex Smith completed 31 of 45 passing attempts for 386 yards. Those accounted for Smith’s best yardage and highest completion rates of the season.

Just as they did against Steve Smith the week before, the Bengals gave up another huge day to an opposing wide receiver. Jeremy Maclin hauled in 11 receptions (third all time for Maclin) and 148 receiving yards (Maclin’s sixth best total of his career).

Through four weeks the Bengals' passing defense is allowing a 94.4 quarterback rating against them. And if you exclude the Oakland game, where the Raiders were forced to use a backup quarterback for much of the game, this boosts their opponent’s quarterback rating up to 98.1 for Weeks 2-4.

If the total passing yardage allowed after four weeks were turned into a quarterback, that quarterback would currently rank fourth in the NFL for the most passing yards.

Is it the defensive play calling by Paul Guenther? Is it the defensive back coaching by Vance Joseph and Mark Carrier? Is it the loss of an old Terrance Newman? Is it the league-leading seven missed tackles by Dre Kirkpatrick? Is it on the pass rush (even though the Bengals rank sixth in the NFL with 11 sacks)? Is it poor coverage by the cornerbacks and safeties?

It’s great that the Bengals are 4-0, and hopefully they will soon be 5-0. But if they continue to allow opponents to move the ball at will against them, it seems this inability to shut down their opponent’s passing games will eventually catch up to them.