Daily Dunk Score Leaders: Each night, the top five Dunk Scores will be updated in real time on NBA.com/Stats. View the top right column on desktop and below Player News on mobile devices.
Dunks provide some of the most electrifying moments in basketball. Whether it’s a gravity-defying leap, an explosive finish through contact, or a windmill slam that ignites the crowd, there’s nothing quite like a dunk to get fans out of their seats. But what if there was a way to quantify the magic behind each slam? With the help of advanced optical tracking systems and cutting-edge AI, that’s exactly what the NBA Dunk Score sets out to do.
The NBA Dunk Score breaks down every dunk using data-driven metrics resulting in an objective score based on technical excellence, athleticism and difficulty — without any bias derived from game context or the players involved.
Ready to dive into how this works? Let’s explore the NBA Dunk Score.
Data Overview
The foundation of any model is the data that goes into it. That’s where the NBA’s optical player tracking systems come in. Using advanced 3D pose detection models, these systems track 29 points on each player’s body with sub-centimeter accuracy, generating 3D coordinates for every movement. All of this is captured 60 times per second.
Dunk Score Overview
The NBA Dunk Score is a live model that analyzes over 25 different attributes of a dunk—each calculated directly from the player tracking data—to assign an objective score. The system is entirely data-driven, meaning the score is independent of external factors like the dunker’s identity, the game’s score, or whether it’s a preseason or playoff game. This makes the Dunk Score a true “technical score,” focused solely on the execution of the dunk itself.
The Dunk Score is broken down into four distinct subscores: Jump, Power, Style, and Defensive Contest —each highlighting a different aspect of the dunk. The Jump subscore is all about the athlete’s verticality and explosiveness in the air. Power captures the raw force of the dunk. Style measures dunk flashiness, quantifying how much creativity the player adds to their dunk. Finally, the Defensive Contest subscore adds context by evaluating how much defensive pressure the dunker faced. Together, these four subscores provide a deeper, more nuanced breakdown of every dunk. Rather than just focusing on the overall score, they give us insight into the different dimensions of the play.
Base Features Overview
Let’s take a closer look at the key attributes that factor into the Dunk Score. These metrics, pulled directly from the 3D pose data via a real-time processing pipeline, are the building blocks of the model. Some features carry more weight than others, but each one helps break down the technical aspects of a dunk:
- Player Vertical: Based on the mid-hip height when the player’s jumping foot leaves the ground versus their peak mid-hip height during the jump.
- Takeoff Distance: The distance from the hoop at the point of takeoff. If the player jumps from one foot, it’s measured from the jumping foot’s big toe. If the player jumps from two feet, it’s measured from the midpoint between the big toes.
- Hang Time: How long the dunker is airborne.
- Maximum Ball Height: The peak height of the center of the ball during the dunk.
- Reach Back Distance: The furthest distance between the player’s head and the ball as it is pulled back from the hoop.
- Ball Speed Through the Rim: How fast the ball is moving as it passes through the rim.
- Total Ball Acceleration: The total acceleration of the ball toward the hoop, accounting for the force the player applies during the dunk.
- Ball Movement: The distance the ball travels over the course of the dunk, minus the takeoff distance. This captures many flashy motions often performed during dunks: Windmill, Double Clutch, Behind the back, etc.
Not all features are continuous — some are boolean (true or false) features that focus on specific stylistic elements, including:
- Reverse Dunk
- 360 Dunk
- Through the Legs
- Alley-oop and Self-Oop: The score is adjusted based on the length of the pass, where the ball is caught, and whether the player catches the ball with one or two hands.
- Tip Dunk: Scaled higher based on how aggressively the player contests for the rebound versus simply being in the right place for an easy tip-in.
The Impact of Defense
Defensive factors are treated as unweighted bonus points beyond the base score. This way, the lack of a defender doesn’t penalize a dunk, but great defense can elevate its difficulty and the overall score. Multiple defenders’ contributions are additive, but each defender’s influence diminishes with every additional body in the mix. Key defensive features include:
- Defensive Contest Level: A combined measure of (1) how close the defender’s body is to the dunker and how directly they are positioned between the dunker and the hoop, and (2) how close the defender’s hand is to the ball, with slight weighting towards the ball-hand-rim angle. If the defender is under or beyond the hoop, they are penalized.
- Alignment Score: Measures how directly the dunker and defender are facing each other, using dot products of their direction vectors and scaled by distance. A chest-to-chest contest would result in a perfect 1.0 alignment score.
- Collision Score: Measures the intensity of contact between the dunker and the defender. It evaluates the sum of their velocity components toward each other, scaled inversely by the distance between them. Two players in very close proximity moving directly at each other at high speeds would have a high collision score.
The model also detects situations where a defender attempts to take a charge or when the dunker jumps over the defender. In these cases, special logic is used to focus on 2D body-based features rather than hand-based features.
Overall Scoring Distributions
Below is a histogram representing the overall distribution of the Dunk Score for all dunks from the 2023-24 NBA season. Most dunks land somewhere in the 20-50 range. It’s a right-skewed distribution, meaning only a select few make it into the upper echelon.
The NBA Dunk Score – launching in the 2024-25 NBA season in Beta – is a groundbreaking way to look at one of the game’s most thrilling plays. By analyzing player movements, defensive pressure, and the physics of flight, dunks can now be compared with objective precision.
