NFL offenses have slowly shortened the field, putting more emphasis on short area quickness and inside slot matchups. These are the league wide averages for AIR YARDS per pass attempt since 2011:

‘17: 8.07
‘16: 8.08
‘15: 8.17
‘14: 8.17
‘13: 8.22
‘12: 8.36
‘11: 8.51#JawsStats

— Ron Jaworski (@JawsCEOQB) March 19, 2018