NFL Analytics Glossary
Plain-English definitions of the terms on this site, with how each one is computed here. For the full picture of the model, see our methodology.
Our metrics
- Combined Drive Efficiency
- Drive efficiency and turnover propensity added together, so a team's rating reflects every way a drive can end short of the end zone: punts, field-goal attempts, turnovers and turnovers on downs. More
- Drive Efficiency
- A team rating for how far drives get before they stall in a punt or field-goal attempt, adjusted for the opponents faced and the game situation. Zero is league average and higher is better, for offense and for defense. More
- Drive Time
- How much game clock a team's drives use for the yards they gain, adjusted for the situation when the drive started. More
- Power Ranking
- An ordering of teams by strength rather than by record. Ours orders teams by simulated win rate against a league-average opponent. More
- Projected Wins
- How many regular-season games a team is expected to finish with: its actual wins so far plus the wins from simulating the rest of its schedule. More
- Simulated Win Rate
- The share of simulated games a team wins outright against a league-average opponent. It is the number our power rankings are sorted by. More
- Turnover Propensity
- A team rating for how often drives end in a turnover (interception, fumble, turnover on downs, safety or blocked kick) for each yard covered, adjusted for opponents and situation. Zero is league average and higher is better. More
- Win Probability
- The model's estimated chance that a team wins a game, from the share of simulated games it wins. A 70% favorite should still lose about 3 games in 10. More
Methods
- Bayesian Analysis
- A statistical approach that describes what we know about a quantity as a probability distribution and updates it as data arrives. More
- Brier Score
- A measure of probability forecasts: the average squared gap between the forecast and what happened (1 if it happened, 0 if not). Lower is better; always saying 50% scores 0.25. More
- Calibration
- Whether forecast probabilities match how often things happen: of all the teams given a 70% chance, about 70% should win. More
- Home Field Advantage
- The edge a team gets from playing at home. Across the NFL it has historically been worth a few points per game and has shrunk in recent seasons. More
- Monte Carlo Simulation
- Estimating the chance of an outcome by playing it out many times with random draws and counting how often it happens. More
- Survival Analysis
- A family of statistical methods for how long something lasts before an event happens. We apply it to drives: how many yards a drive survives before it ends. More
Football stats
- EPA (Expected Points Added)
- The change in a team's expected points from before a play to after it. Positive EPA helped the offense; negative EPA helped the defense. More
- Field Position
- Where the ball is on the field, usually given as yards from the opponent's goal line. Drives that start closer to the end zone score more often. More
- Red Zone Efficiency
- The share of drives reaching the opponent's 20-yard line that end in a touchdown rather than a field goal or no points. More
- Success Rate
- The share of plays that count as successful, commonly a gain of 40% of the yards needed on first down, 60% on second down and 100% on third or fourth down (definitions vary). More
- Third Down Conversion Rate
- The share of third-down plays that gain a first down or score a touchdown. More
- Time of Possession
- The total game clock a team has the ball. It reflects play style and game script as much as quality, so it predicts winning only weakly. More
- Yards Per Play
- Total yards gained divided by offensive plays. A simple, widely used measure of offensive efficiency. More
Betting terms
Explained for reference only. Nothing on this site is betting advice; see our disclaimer.
- Moneyline
- A wager on which team wins outright, with no point spread. The odds are written as positive or negative numbers that set the payout; they also imply a win probability that includes the sportsbook's margin. More
- Over/Under (Total)
- A sportsbook number for the combined score of both teams; wagers are on whether the final total lands above or below it. More
- Point Spread
- A margin set by sportsbooks to make two teams roughly even for wagering. A team listed at -7 must win by more than 7 points to "cover". More