HOUSTON—There is a number guiding the basketball philosophy of the Houston Rockets. This number that informs every decision by the NBA’s wonkiest team and explains the marvelous season of James Harden is a very specific one: 1.16. That’s the number of points per possession they have to score to be the best offense in the history of basketball.

It’s such a powerful number that Rockets coach Mike D’Antoni, who has long been known for strategies that pushed the boundaries of his sport, realized he wasn’t pushing the boundaries enough as soon as he came here and immersed himself in Houston’s analytics.

“I never had this data,” D’Antoni said in reference to points per possession. “Like, wait a minute. This (play) gives us 0.8, this gives us 0.9, this gives us 1.2. Why don’t we do the 1.2 every time? Why do we do the 0.8s and 0.9s?”

Mike D’Antoni turned himself into basketball’s Marie Kondo. He decluttered the Rockets. But unlike the Japanese tidying guru, D’Antoni wasn’t trying to spark joy. His benchmark was more objective: 1.16 points per possession. “Anything above that, we try to keep,” he said. “Anything below that, we have to figure out why and get it out.”

The obsession with 1.16 is the driving force behind the most peculiar strategy in basketball. It’s the reason the Rockets have taken the NBA’s pursuit of peak efficiency to an extreme.