That streak might be coming to an end this year with a deep quarterback class.
The Ravens are expected to discuss taking a quarterback, perhaps a future starter, to develop behind Flacco. The timing seems right considering Flacco turns 33 later this month and has dealt with serious injuries the past two seasons.
Ravens coach John Harbaugh called a question about whether Baltimore will draft a quarterback in 2018 a "fair" one.
"It is something that we will talking about for sure," Harbaugh said at his season-ending press conference. "Every position, certain positions are going to be more important than others, but when you have a veteran quarterback at this stage, that is the time you are always looking for a young backup."
The top quarterbacks in this draft -- UCLA's Josh Rosen, USC's Sam Darnold, Wyoming's Josh Allen and Oklahoma's Baker Mayfield -- have been projected to go in the first 15 picks. The Ravens, who have the No. 16 overall pick, aren't expected to take a quarterback in the first round.
Baltimore can find a quarterback in the middle rounds, possibly in the third round, where the Ravens have two picks (one is a compensatory pick for losing offensive tackle Rick Wagner). Quarterbacks who could fall to that point are Oklahoma State's Mason Rudolph, who has good size (6-foot-5) and average arm strength but lacks great vision; Washington State's Luke Falk, an accurate thrower who needs to add bulk (compares to Kirk Cousins); and Memphis' Riley Ferguson, who has an arm to stretch the field and broke Paxton Lynch's single-season school touchdown record with 32.
The Ravens need a backup because Ryan Mallett isn't expected to be re-signed in free agency. Baltimore hasn't drafted many quarterbacks in recent years. Since taking Flacco in 2008, the Ravens have selected two passers (both in the sixth rounds): Tyrod Taylor (2011) and Keith Wenning (2014).
"I do not think that jeopardizes Joe at all," Harbaugh said of drafting a quarterback this year. "He is our guy, and I am excited about our chances next year having a great season, and Joe is too. If we draft a quarterback, if it turns out to be the thing we do, it is only going to make our team stronger."
The Ravens are contractually married to Flacco at least through 2019 and perhaps through the 2020 season, when Baltimore could release Flacco and gain $20 million in cap space. The sides could also rework his deal at that point to lower his cap hit and keep him in Baltimore.
Another reason why the Ravens have to think about their quarterback of their future is Flacco's play and injuries. Since being Super Bowl MVP in 2012, Flacco has been the NFL's No. 36 passer, throwing 98 touchdowns and 74 interceptions for an 82.1 rating. That ranks behind Brian Hoyer and Ryan Fitzpatrick.
One of the more durable quarterbacks over the past decade, Flacco has dealt with increasing injuries. In 2016, he missed all of the offseason workouts because of his recovery from knee surgery. Last season, he was sidelined for all of training camp and the preseason due to a lower back injury.
Returning to practice eight days before the season opener affected Flacco's productivity. In the first 10 games, Flacco threw nine touchdowns and 11 interceptions. In his last six, he totaled nine touchdowns and two interceptions.
"To say that [back injury] was not a factor in our passing game early combined with the personnel issues that we had there, it just wouldn’t be fair to Joe," Harbaugh said. "I think a whole training camp, a whole offseason of continuing to work on those things going into a season are going to make it better going into the season."