Former Kia MVP winner Kevin Durant is among the NBA’s leaders in the Gravity stat.
Gravity is a new way to quantify how much a player pulls defenders out of their normal assignments, essentially measuring how much attention they draw compared to what the spacing on the floor predicts.
In simple terms, Gravity tells us who forces defenses to react, even before they touch the ball.
Historically, the “eye test” has been the predominant way for spotting how certain players impact a defensive scheme, whether or not they have the ball. Coaches and fans have instinctively known which players demanded extra attention, but now, with the power of AWS AI and Machine Learning, the eye test just got smarter with the introduction of a new official NBA stat: Gravity.
Gravity is the NBA’s first stat designed to quantify how much defensive pressure an offensive player draws both on and off the ball. Leveraging positional tracking data and powered by advanced Machine Learning models, Gravity scores show how much a player distorts a defense – opening driving or passing lanes, shifting rotations, and creating opportunities for teammates.
The NBA’s optical tracking system uses 3D pose detection to track 29 points on every player’s body, 60 times per second. Those detailed body-position coordinates fuel the Machine Learning model, allowing it to capture every movement and spatial relationship on the floor.
The Gravity model compares the defensive pressure a player would receive on average based on the location of the ball and their position on the floor (Expected Defensive Pressure Score) to the pressure they actually draw (Defensive Pressure Score). The model learns how defenders typically behave in each scenario, and measures deviations that signal defensive adjustments. The result is a Gravity differential that measures how much attention a player pulls from the defense beyond expectation.
The Gravity score measures frame-by-frame impact, expressed as a normalized value on a -100 to 100 scale, with 0 reflecting the league average. Above 0? You’ve got pull. Above 80 off-ball? Defenses are terrified of you before you even catch the ball. Above 90? You’re bending the floor and you’re a scorer the defense simply cannot blink on. Basically, that player should be guarded from the parking lot.
Why does it matter? Gravity captures a player’s ability to impact the game before the play even begins. It highlights players who generate high-value spacing, draw mismatches, and make their teammates’ job easier – often without taking a shot. With Gravity, this invisible impact becomes visible, and the off-ball impact becomes measurable.
Gravity is part of the next generation of stats and insights that we’re bringing to fans in real-time with the power of AWS AI.
