According to Pro Football Focus, since 2008 Joe Flacco Flacco was one of the NFL's worst against unblocked pressure.
"Perhaps it's partially the offensive system focused on throwing the ball down the field or maybe it's Flacco's being handcuffed with regard to pre-snap audibles in his early years, but he's certainly not at his best in the quick game throwing hot routes against unblocked blitzers," wrote PFF's Steve Palazzolo. Flacco has completed just 42.1 percent of his passes with seven touchdowns, six interceptions and a 4.4 yards-per-attempt average on plays when facing unblocked pressure.
how is Joe Flacco the worst NFL worst Qb.
Ummm they didn't say Flacco has been the worst QB. They said he has been the worst against unblocked pressure. An example would be if Rice missed the block on a blitzing safety or something of the sort.