On top of that, Gelfand has a regular on-court presence, which is also unusual for an “analytics guy.” He is the go-to rebounder for the reserve guard Shaun Livingston, who bonded with Gelfand almost immediately through their shared Illinois roots and who will not trust anyone else with that job after practices and shoot-arounds — despite Gelfand’s self-professed proclivity for “getting my glasses knocked off” in practice settings.

“He’s like the little brother of the team,” Livingston said.

Gelfand, 31, is the youngest of three siblings, and still struggles to comprehend how he landed beside Livingston — a star in Peoria, Ill., while both were in high school — with a franchise that sits just one win away from its third N.B.A. championship in four years. Part of that disbelief, he admitted, stems from being raised in what he described as “the most unathletic family in the world.”

But he was hooked on sports from a young age and entranced by the Chicago Bulls’ dynasty. “The Jordan, Pippen and Kerr Bulls,” Gelfand said, understandably paying a higher tribute to Kerr’s role in Chicago’s success than most would.

He was an annual science fair participant in his youth, but his time at George Washington University sparked the gumption Gelfand needed to scrap plans to go into political analytics and “go all-in” on his dreams. An internship with the sports agency Octagon while he was in graduate school at Georgetown was his entree to the N.B.A. But he quickly soured on that side of the business when Octagon lost its bid to represent the future N.B.A. All-Star Gordon Hayward to Priority Sports.

“That just killed me,” Gelfand said. “I realized then that I loved sports, but I loved the game. I wanted to work for a team.”

The silver lining at Octagon: Gelfand made basketball connections and persuaded the former N.B.A. head coach Eric Musselman to hire him as an unpaid intern in 2010-11 for the Musselman-coached Reno Bighorns in the N.B.A.’s official minor league. The Bighorns were the shared affiliate of the Warriors and the Sacramento Kings, enabling Gelfand to bond with the Golden State assistant general manager Kirk Lacob. Lacob was making frequent trips to Reno to monitor the progress of Jeremy Lin, who was a rookie.