In basketball, physics predicts how big a lead your team needs to win

Ronald Martinez/Associated Press

In basketball, physics predicts how big a lead your team needs to win

Physics isn’t all about discovering new subatomic particles and describing the fundamental forces that hold the universe together. It’s also about knowing just how little of a basketball game you need to watch in order to maximize your excitement and maybe even predict who will win. A group of physicists analyzed lead changes in team sports, including football, hockey, and basketball, and discovered that in basketball especially, the number of lead changes within a game closely follows the mathematical rules governing what’s called a “random walk,” or a path that consists of a series of random steps. Certain factors—possession changes after scoring and even, um, which team is better—are, mathematically speaking, “inconsequential departures” from the random walk model, the researchers write in a forthcoming paper in Physical Review E. But there are a few times in the game where lead changes are statistically likely to take place: the first few minutes, and the last. This is also when the biggest point difference is likely to occur, the researchers write. They also offer up an equation that can predict when a lead is a safe, based on the size of the point difference and the time left in the game. If your team is up by 10 points with about 8 minutes left in the game, for example, you can be 90% sure it’s going to win; the same goes for an 18-point lead at the end of the first half. Something to think about if you’re trying to calculate the best time to bail early from game 5 of the NBA finals on Sunday.