Lost in the fact that the Baltimore Ravens swept the season series in 2011 was how successful the Cincinnati Bengals and rookie quarterback Andy Dalton were at moving the ball against a defense that sent four players to the Pro Bowl.

In the 31-24 loss in Baltimore on Nov. 20, the Bengals gashed the Ravens for 483 total yards, their most in a span of 72 games, as Dalton broke his own franchise rookie passing record with 373 yards.

Six weeks later, in a 24-16 home loss in the season finale, the Bengals racked up a respectable 336 yards against a Baltimore defense that finished the year ranked third in the NFL is yards allowed.

The difference in both of those games is the same thing that figures to be the difference Monday night in Baltimore – turnovers.

“Turnovers have been the key to this series,” Bengals head coach Marvin Lewis said. “It’s what’s important. You have to possess the football. It’s the recipe of the AFC North. It’s the recipe of the National Football League. If you have one more turnover than your opponent, right now, you can take that and finish the season at 10-6 since 2000. It’s an amazing thing.”

Especially in the Ravens-Bengals series, where the team that finishes on the positive side of the turnover differential has won the last 13 games. Even a push has been beneficial for the Bengals, who are 4-1 the last five times the turnover differential was even.

“I’ve done a study on all of the series in our division, and it’s the key to the division,” Lewis said. “If you maintain the ball, you have an opportunity to win the game.”

Since 2003, Baltimore ranks third in the NFL with a plus-36 turnover differential. The Bengals are fifth at plus-32, but they finished 2011 dead even, including minus-3 against the Ravens.

In last year’s finale, Jermaine Gresham lost a fourth-quarter fumble in Baltimore territory with Cincinnati trailing just 17-13. Three plays later, Ray Rice went 51 yards to give Baltimore an 11-point lead with less than six minutes to go.

In the November loss in Baltimore, Dalton had the first three-interception game of his career to offset his record-breaking yardage.

“A couple of the turnovers we had last year — (Dalton) had three interceptions strapped to him, but zero of them were his responsibility,” Lewis said. “Basically we had some error with the guys. That’s part of it, too. That all falls underneath us. We all win, we all lose.

“We’ve stated from the start that we made changes on offense to be more reliable.”