NFL Analytics Glossary
Understanding the terminology used in modern football analytics. Click on any term to learn more about how we use it in our analysis.
Metrics
- Defensive Drive Efficiency
- A measure of how effectively a defense prevents the opposing offense from scoring. Lower values indicate a more effective defense.
- Drive Efficiency
- A measure of how effectively a team moves the ball and scores on offensive possessions. Higher drive efficiency indicates a team that consistently converts drives into points.
- EPA (Expected Points Added)
- The difference between the expected points before and after a play. Positive EPA means the play added expected points for the offense; negative EPA means it helped the defense.
- Power Ranking
- A ranking system that attempts to measure team strength beyond simple win-loss records. Our power rankings incorporate offensive and defensive efficiency metrics.
- Red Zone Efficiency
- The percentage of drives that enter the red zone (inside the opponent's 20-yard line) that result in touchdowns rather than field goals or no score.
- Success Rate
- The percentage of plays that are considered successful. A play is typically successful if it gains 50% of needed yards on 1st down, 70% on 2nd down, or 100% on 3rd/4th down.
- Third Down Conversion Rate
- The percentage of third down plays that result in a first down or touchdown. Critical for sustaining drives and scoring.
- Turnover Efficiency
- A measure of ball security (offensive) or takeaway ability (defensive). Teams with better turnover efficiency protect the ball on offense and force turnovers on defense.
- Win Probability
- The estimated likelihood that a team will win a game, expressed as a percentage. Our models calculate win probability based on team strength, home field advantage, and other factors.
- Yards Per Play
- The average number of yards gained per offensive play. A simple but useful measure of offensive efficiency.
Methodology
- Bayesian Analysis
- A statistical approach that updates probability estimates as new data becomes available. In football analytics, Bayesian methods help us incorporate prior knowledge about team strength while adjusting for new game results.
- Survival Analysis
- A statistical method that models the time until an event occurs. In football, we use it to model drive outcomes - how likely a drive is to result in a touchdown, field goal, or turnover.
Betting
- Moneyline
- A bet on which team will win the game outright, regardless of the point spread. Odds are expressed as positive or negative numbers indicating the payout.
- Over/Under (Total)
- A bet on whether the combined score of both teams will be over or under a specified number set by oddsmakers.
- Point Spread
- The predicted margin of victory for the favored team. A team favored by -7 is expected to win by 7 points.
Concepts
- Field Position
- The location of the ball on the field, typically expressed as yards from the goal line. Field position significantly impacts scoring probability and drive outcomes.
- Home Field Advantage
- The statistical benefit teams receive when playing at home. Historically worth about 2-3 points in the NFL, though this has decreased in recent years.
- Time of Possession
- The total time a team controls the ball during a game. While not always predictive of winning, it indicates ball control and can affect defensive fatigue.