RB Christian McCaffrey had 867 receiving yards last year, while WR Chris Godwin had 842 receiving yards. But they got there in very different ways. McCaffrey gained just 16 of his receiving yards via “air yards” — yards gained on catches based on yards in the air the pass traveled from the line of scrimmage to the receiver — and 851 of his receiving yards came on yards gained after the catch. Godwin had 597 air yards, and 245 yards after the catch.

That’s an extreme split, but consistent with the general rule that running backs gain very little air yards (many of their receptions come from behind the line of scrimmage, which produces negative air yards) and a lot of yards after the catch. For wide receivers, about 60-70% of their yards come through the air, with the remainder coming after the catch.

Tight ends are interesting, by virtue of usually landing somewhere in between those two marks. The graph below shows data from the 2018 season, with air yards shown on the X-Axis and yards gained after the catch shown on the Y-Axis. Running backs are in red, tight ends are in green, and wide receivers are in blue.

George Kittle really stands out for his YAC: he gained yards after the catch like a running back, and had 7 receptions on “short” passes that still gained over 35 yards, due to his remarkable YAC.

Players like Giants TE Evan Engram and Steelers TE Vance McDonald operated almost like running backs; for both players, over 60% of their receiving yards came after the catch. Meanwhile, Patriots TE Rob Gronkowski is more like a wide receiver: only 27% of his receiving yards came after the catch.

And Eagles TE Zach Ertz stands out in a similar way: only 30% of his yards came after the catch. He really operated like a wide receiver for this year, albeit one who wasn’t a great deep threat.  Who operated like a deep threat? Well that would be Mike Evans, of course, who always is among the lead leaders in air yards and percentage of receptions that go for first downs.