nfl qbr is the new quarterback rating stat that ESPN introduced in 2011. It tries to separate a player’s performance from his teammates’ and tie it to winning rather than pure volume or raw efficiency. It does so by incorporating game context and up-weighting critical plays. It also attempts to be more objective and predictive than Passer Rating by taking things like depth of target and receiver yards after catch into account. Despite its many attempts to be more comprehensive and accurate than Passer Rating, it doesn’t appear to do much better of a job at correlating with win/loss records or predicting future margin of victory.
The basic idea behind nfl qbr is to divide a passing play’s expected points added (EPA) by the sum of all the offensive and defensive factors on that play. Then it assigns credit to the quarterback based on how incremental the play was, which is compared to historical outcomes in similar situations – down, distance and time remaining at snap. The resulting score is then multiplied by the quarterback’s current win probability and summed up to give a score out of 100.
This score is then compared to the league average to provide an overall snapshot of a quarterback’s success. Average NFL quarterbacks typically have a QBR around 50, while top-tier/Pro Bowl caliber quarterbacks usually have a QBR in the 75 range.
While this is a very simple explanation of how the QBR works, there are many more details that go into its calculation and interpretation that are not made public. For example, the QBR considers the difficulty of each individual pass and gives varying amounts of credit to the quarterback, his receivers and the offensive line based on how far the ball traveled in the air and how many yards were gained after the catch compared to what would have been expected. This is how you get the weird results where Tim Tebow gets a higher QBR than Aaron Rodgers in their respective games on October 9.
It also takes into consideration things that aren’t necessarily passes such as sacks, interceptions and turnovers. This is because it’s important to look at the whole picture when evaluating a quarterback’s performance. It also looks at how the quarterback performs in different types of games and against varying quality opponents. For instance, a 30 yard completion in garbage time against a bad defense will be much more impressive than a similar pass when they are down 40 and playing their third stringers.
Despite some issues, the new QBR is certainly an intriguing concept that should be examined and experimented with a lot over the next few years. While it’s not a magic bullet, it may help football handicappers gain more insight into how to make winning NFL picks. If nothing else, it will definitely keep people talking!