Perhaps blame it on a rash of big-name quarterback injuries, but the 2017 NFL season did not continue the trend of new passing records being set league-wide. The completion percentage (62.1 percent) and sack rate (6.4 percent) dipped to their lowest marks since 2013, and the interception rate (2.5 percent) was higher than it had been in the previous two seasons. (Thanks, DeShone Kizer).
As for throwing short of the sticks on third down, which is what ALEX looks at, that also fell to its lowest level since 2009. In this case, the lower number means the shorter the pass is traveling relative to the marker.