The QRI is a model that measures quarterback performance in high-leverage situations as a way to quantify the level to which a team relies on that player’s ability when it matters most. These high-level situations include third- and fourth-down plays and late-game sequences all while filtering out plays in which the in-game win probability is greater than 80% for either team. In other words, when the game is on the line, this metric attempts to evaluate how well a quarterback has gotten the job done.
Passing- and rushing-related metrics within the model include versions of:
- Expected points added (EPA)
- Success rate (play with a positive EPA is considered a successful play)
- Win probability added (WPA)
Using the metrics, the model calculates a rating similar to Wins Above Replacement (WAR) in baseball. The rating represents how many wins better the given QB has been than a replacement-level QB in the aforementioned high-leverage situations and then prorated over the course of a 17-game season.
For a more thorough evaluation,
the index includes data from all games since the start of the 2022 season (for applicable players) with recent games weighted more heavily. Until more games are played, rookies and newer starters have smaller sample sizes and will be more susceptible to bigger swings.