Last week, the brothers helped Central High capture the school's sixth consecutive Public League title, while Jacob earned the individual championship for the second straight year by shooting a 6-over-par 37 for nine holes.
On Tuesday, they will compete alongside four other Lancers in the PIAA District 12 championship tournament at Penn Oaks Golf Club in West Chester.
Coach Mike Horwits said no Lancer in recent memory has advanced to qualify for the PIAA state championships.
"At the beginning of the season, Jacob told me that was one of his goals," Horwits said. "At the end of the day, I'm just so proud of how well they've matured as leaders."
The 17-year-olds from Mount Airy began playing golf seven years ago at a weeklong summer camp with the Department of Recreation.
The Spivacks try to play together each weekend at a course near their house. The brothers maintain a friendly competition, while still offering each other pointers.
"When you hit a bad shot, we'll say if your stance is wrong or you might want to swing easier," Daniel said. "But it's not that much, because you don't want to help your opponent."
Jacob's career best is 4-over par, while Daniel's is 6-over par.
Daniel said his brother wins more often, but Daniel has been winning more recently. Although they aren't paired for league matches, they will compare scores afterward and talk about individual holes.
A few summers ago, they volunteered for the First Tee program of Philadelphia, a community service project that teaches the sport to youths. Along with helping others, the brothers received guidance from a PGA pro assigned to the clinic who aided their game.
Working with kids was "fun, but hard sometimes," Jacob said. "You had to get them in the proper grip and show them how to stand."
Horwits also coaches the Spivack brothers in tennis in the spring. He said they are two of the most enjoyable students he's coached; he also teaches Daniel in social studies.
"There's a lot of satisfaction on my part to be able to coach them," Horwits said. "It's an honor to coach them - you don't get that often."
Contact staff writer Matt Breen at mbreen@phillynews.com or @matt_breen on Twitter