Each week, it is easy to figure out which players had the most value in fantasy football. But what about the question of which players had the most value in actual, real life NFL football? It isn't enough to add up yards and touchdowns. A running back who piles up a ton of two-yard carries isn't really helping his team win and he's not really responsible for a touchdown if the quarterback completed 90 yards worth of passes to get the team down to the one-yard line. A wide receiver who has five catches that each gain a first down is helping his team more than a receiver who catches one touchdown but lets the defense bat away four different incomplete passes on third down. And if your defense picks off the other quarterback when he's backed up against his own end zone, how much credit does the offense really deserve for the ensuing touchdown drive that might go all of eight yards?
At FootballOutsiders.com, we've developed a system called Yards Above Replacement (YAR) that gives us a pretty good idea of which players did the most to help their teams win or lose. The success of every single NFL play is judged based on yardage gained towards both a touchdown and a first down. Then each play gets compared to the NFL average on similar plays, based on down, distance and other variables. Once we have enough data for the season, we also adjust for the quality of the opposing defense. (It's important to note that the first week's numbers are not adjusted for opponent.) Each player's performance is then translated into an approximate number of yards representing what such success (or failure) is worth when compared to a generic bench scrub (also called a "replacement player," or, by his parents, "Billy Joe").
Need an even quicker and easier way to see how good a player was? Then use another stat we call Effective Yards (EYds). Effective Yards take the player's performance, adjusted for situation and opponent, and puts it on the exact same scale as standard yardage. If a player has more Effective Yards than Yards, he was better than standard stats make him look. If he has fewer Effective Yards, he was worse than standard stats make him look.
Each Monday in Quick Reads, we'll use YAR and Effective Yards to take a look at the best and worst quarterbacks, running backs, and wide receivers of the week.
A more extensive explanation of these numbers can be found here.