Air Yards are the total number of yards thrown toward a receiver on a play in which he is targeted. They act as a complementary statistic to normal stats, like targets and receiving yards as an additional layer of context and opportunity. For fantasy football, the deeper the target, the higher the expected number of fantasy points. Air Yards were pioneered in fantasy football by Josh Hermsmeyer.
Some important terms to know when reviewing this data.
WOPR – Weighted Opportunity Rating. WOPR is a weighted combination of the share of team targets a player receives and the share of team air yards. You can read more about it at Rotoworld.
RACR – Receiver Air Conversion Ratio. The formula is (Receiving Yards/Air Yards). RACR is an efficiency metric that rolls up catch rate and yards after the catch into one number. It can also be thought of as the number of receiving yards a player creates for every air yard thrown at him. You can read more about RACR here.