The number of yards a team or player acquires per game helps teams and analysts determine the quality of the team or player. It also helps evaluate the defense based on how many yards they allow per game. This statistic is calculated by dividing the total number of yards gained over a given period of time (usually a season) by the number of games in that same period of time.
This is an officially tracked statistic because it is so helpful in evaluating different facets of a team or a player. A modern NFL team will want to average at least 300 yards per game in order to be competitive, while a player's desired yards per catch is dependent on their position. For example, O.J. Simpson owns the record for most rushing yards per game over the course of a season with 143.1, while Wes Chandler owns the record for most receiving yards per game over the course of a season with 129. The active record holders in those categories are Adrian Peterson (92.4) and Andre Johnson (79.5).