His $22.1 million per-year average ended Aaron Rodgers' nearly three-year reign as the league's highest-paid player.
Just 15 months later, Flacco's deal is far from record-setting. He has fallen to No. 5 after Derek Carr's five-year, $125 million extension last week.
This season, Carr, Andrew Luck, Drew Brees and Kirk Cousins all have contracts that average more than Flacco's. It should be only a matter of time that he's out of the top five, because Matthew Stafford is entering the final year of his contract.
Flacco's one-time "elite" contract continues to draw criticism because he hasn't played up to it. He is 33rd in passer rating (82.5) in the four seasons in which he has ranked among the highest-paid quarterbacks. Over that span, he has a 29-29 record and the third-most interceptions (61).
The Ravens' rationale in paying Flacco this much is his postseason résumé. The 32-year-old won a Super Bowl in 2012, owns the second-most playoff victories since 2008 (only Tom Brady has more) and recorded a 104.1 passer rating (24 touchdowns and four interceptions) in the postseason from the 2010 season onward.
In comparison, Carr has thrown 81 touchdowns in three seasons but hasn't won a playoff game. Luck has been to three Pro Bowls yet has a 3-3 record in the postseason. Cousins passed for more than 4,000 yards each of the past two seasons but has a losing record (19-21-1) as an NFL starter.
Of the top five highest-paid quarterbacks, only Flacco and Brees have led their teams to a Lombardi Trophy.
At the end of last season, the Ravens stressed the need to get Flacco to play up to his level of compensation. In 2016, one year removed from tearing two ligaments in his knee, he rushed his throws at times (opting for checkdowns) and didn't see the field as well as he did in previous seasons (which was evident on some of his interceptions).
This offseason, Baltimore did more to help its defense than its offense. Flacco lost four of his top six targets from last season, and the Ravens' most significant additions were wide receiver Jeremy Maclin and running back Danny Woodhead.
There is pressure for Flacco to carry the offense, no matter what the supporting cast. Even though he has slipped in terms of average salary, Flacco has the NFL's highest salary-cap number at $24.55 million.