Bengals factoid: Preventing first downs

One measure of a defense's success can be seen in how well it prevents an opposing offense from getting first downs.

Last season, the Cincinnati Bengals were quite good at doing that. They ranked third in the league in first downs allowed, giving up 282. The most a defense gave up in 2013? It was the 388 chain-moving plays permitted by the Cowboys.

This Thursday's factoid looks specifically at one area the Bengals were particularly successful at when it came to limiting first-down chances for opposing offenses.

The number of the day: 29.0.

Out of the 614 passing attempts the Bengals allowed last season, opposing offenses converted first-down passes on just 29 percent of those throws, according to ESPN Stats & Information. That was the lowest first-down-per-attempt conversion percentage in the league. At 29.8 percent, the Seahawks were the only other team that allowed fewer than 30 percent of the passes attempted on them to be converted for first downs.

On the other end of the spectrum was Washington, which allowed a league-high 39.7 percent of passes attempted against it to be turned into first-down receptions.

It wasn't only in the first downs per pass where the Bengals had a solid conversion rating. They did well in the first downs per rush category as well. They ranked fifth in the league last year in limiting first downs per rushing attempt. Of the 385 carries opposing offenses had against them, the Bengals permitted teams to convert first downs on only 18.7 percent of them. The Jets, Lions, Ravens and Cardinals were the only teams with lower first-downs-per-rush conversion ratings.

Why are the conversion percentages lower for rushing attempts than passing ones? The same reason yards-per-carry averages are typically lower than yards-per-reception averages. It's simply easier to gain yards in the air than it is to consistently pick up big chunks on the ground. That's long been a truism in the NFL, and likely forever will be.

Regardless which is easier to contain, the fact is the Bengals were pretty good at getting offenses to third down and not letting them convert last season. The aforementioned first-down conversion ratings are evidence of that, as is the 32.9 percent overall third-down conversion rating Cincinnati had in 2013. Detroit was the only team that had a better third-down conversion rating. All of the statistics discussed here are related, and are among the reasons the Bengals ended up having the league's third-best defense.

The question now becomes if the Bengals will be able to obtain similar numbers this fall when they field a defense for the first time in seven years without Mike Zimmer in charge of it. Newly promoted defensive coordinator Paul Guenther believes the transition from Zimmer will be smooth, and that his talented, mostly returning defense will be able to pick right up where it left off last year. The only true losses this offseason were defensive end Michael Johnson (signed away in free agency), linebacker James Harrison (released) and safety Chris Crocker (wasn't re-signed in free agency).

It's the Bengals' "additions" that could be the real game-changers. Along with signing veteran defensive back Danieal Manning and drafting the likes of cornerback Darqueze Dennard and defensive end Will Clarke, the Bengals also will see corner Leon Hall, defensive tackle Geno Atkins, safety Taylor Mays and outside linebacker Emmanuel Lamur return from injuries that cut short their 2013 seasons. One could argue those gains will greatly outweigh the losses -- from Zimmer to Johnson -- the Bengals had this offseason.