Definition of Completed Air Yards (CAY)

What does the term "completed air yards" mean in the world of football? What is meant by the term "completed air yards", or CAY?

Completed air yards refers to the total distance that a thrown ball travels from:

Point A - the Line of Scrimmage

to

Point B - where the ball is caught

So, let's say that Josh Allen throws the ball to Stefon Diggs, who is immediately tackled.

The pass was a 7-yard completion, meaning that the ball travelled 7 yards from the line of scrimmage to Stefon Diggs, who was immediately tackled.

So, in this case, the completed air yards would be 7 yards.

Now, what if Diggs broke the tackle and took it to the endzone?

The completed air yards would still be 7 yards, as the CAY (completed air yards) include the distance from the line to scrimmage to the point where Stefon Diggs MADE the catch. Any yards-after-completion don't get added to the Completed Air Yards equation.

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Completed Air Yards indicate how far a quarterback is throwing the ball down the field, though the stat is not at all indicative of how good an offense is.

For instance, a team that makes liberal use of pass-catching running backs (such as the Chargers with Austin Ekeler) will have a lower Completed Air Yards number than, say, the Miami Dolphins, who like to throw down the field to Tyreek Hill and Jaylen Waddle.