From an AY/A perspective, the worst (defense adjusted) passing seasons of all time are:

1986 Jack Trudeau (-1075 yards vs expectation)

2016 Osweiler (-1017)

2001 Weinke (-1016)

At his current pace, Josh Allen is on track to set the record for the most costly season by 15-20%. pic.twitter.com/jWVRiW0Uvt

— Justis Mosqueda (@JuMosq) October 11, 2018