OAKLAND, Calif. — The third quarter ended, and the Warriors and the Thunder huddled to plot strategy for the fourth. Between them, seated at midcourt behind the scorer’s table, a man named Brett Yamaguchi had a game plan of his own.

“O.K.,” he said into the microphone attached to his headset. “Let’s drop.”

Hidden in the rafters of Oracle Arena, 12 workers on the catwalks began releasing 100 small parachutes, each holding a McDonald’s gift card. In a dark booth at suite level, someone clicked a computer to change the graphics on the video scoreboards to reflect the sponsor. Nearby, a man at a control board set the 66 moving spotlights in the ceiling in motion. Someone else triggered the nearly 20,000 light-up bracelets that had been given to fans to blink red and yellow. The in-house D.J. played the Gap Band’s “You Dropped a Bomb on Me.”

Most of the fans stood, looking and reaching skyward for the gifts as they slowly descended. A small digital clock on each basket, below the shot clock, counted down the seconds to the end of the timeout. The last parachute was caught, the fans still standing, just before the ball was inbounded to start the fourth quarter.

“There was still a lot of hope at that point,” Yamaguchi said later, minutes after Oklahoma City had upset Golden State, 108-102. Around him, fans shuffled quietly out of the arena and the dozen workers in the catwalks made their way down. They had stayed up there for the fourth quarter, intending to drop 50 pounds of confetti to celebrate a victory.