Brooks’s mother, Lee, raised seven children, working multiple jobs to support the family, and for several years as a single mother. Scott, the youngest, was just 2 when his father left. His mother’s strength and stubborn drive would provide the template for Brooks’s unlikely career — a grinding path through three minor leagues, seven N.B.A. cities and the constant threat of the waiver wire.

“I had to make it as a worker, as a guy that came in to do my job every day,” Brooks said. “And that’s how she does it. She still works every day, and she’s 79 years old. She does her job every day.”

That work ethic kept Brooks in the N.B.A. for 11 seasons and propelled him through the assistant coaching ranks until he rose to head coach in Oklahoma City in 2008. Less than four years later, he has his team in the finals. The Thunder trail the Miami Heat, two games to one.

As a 5-foot-11-inch, 165-pound point guard, Brooks stood almost no chance of an N.B.A. career after going undrafted out of California, Irvine in 1987. He was too small, too slow. He played 11 seasons, for seven franchises, winning a championship with the 1994 Houston Rockets while acquiring a reputation as a relentless competitor and diligent pupil.

Coaches loved Brooks for his passion and toughness, the sort of qualities that teams need on the bench and in scrimmages. So when one team cut him loose, another was always waiting to pick him up. Brooks was traded four times — three times for a second-round pick.