After Bullis guard Brittany Jackson (with ball) committed to George Mason University, the team named a new coach and joined a different conference. (Katherine Frey/The Washington Post)

When Bullis guard Brittany Jackson committed to George Mason University, it was to play for Coach Jeri Porter in the Colonial Athletic Association.

When she arrives at GMU, she instead will be playing for Coach Nyla Milleson, hired in April, in the Atlantic 10 Conference, which the Patriots will join July 1.

So the GMU program that Jackson will be joining is vastly different than the one that she pledged to all those months ago. But her eagerness to play for the Patriots has not waned.

“It was a little bittersweet for me personally because I’d already developed a relationship with the coaches and I had been to a few of the games,” Jackson said. “I was just kind of getting a feel for the CAA. I think the A-10 is a harder league than the CAA.

“I’m glad this decision was made earlier rather than later. Since I’m coming in as a freshman, it won’t affect me as much, and I’m definitely excited for the season and for the A-10.”

On some level, Jackson can relate to what the returning Patriots will be experiencing this season. She had a new coach at Bullis, Rod Hairston, her senior year. She had to learn his style and also break him into the program in a way, along with fellow senior Dazia Hall (Richmond) and others.

“We really were the ones who knew the dynamics of Bullis basketball,” Jackson said. “Coming into Mason, I still haven’t played in a real game or practiced with these girls. I think it’s definitely a different story coming in as a freshman and not being well-versed in the team. You have to find your way and mold into the chemistry of the team rather than being a senior on a team where you basically created the chemistry.

“Considering the season that Mason had this past year, I’m hoping that this coaching staff will help rebuild the chemistry and we’ll have a stronger season. It’s really not even an option because we’re going into the A-10 and we have to build that chemistry before we go out there for battle.”

GMU finished 9-21, for its ninth consecutive losing season, so the jump to the A-10 could be a challenge. The schedule includes home-and-home dates with Dayton (28-3, 14-0), George Washington (14-16, 7-7), old teammate Hall with Richmond (16-15, 6-8) and La Salle (8-21, 4-10).

Milleson joins the program after going 105-87 in six years at Missouri State, with three WNIT berths. She replaces Porter, who resigned after five seasons and a 51-100 record, including a 60-46 loss to bottom seed UNC-Wilmington in the opening round of the CAA tournament, the Patriots’ seventh loss in the last eight games.

GMU’s top scorer was senior guard Rahneeka Saunders (Riverdale Baptist). Former All-Met Player of the Year Taylor Brown (McNamara) had to sit out this past season after transferring from Georgetown. Kyana Jacobs (Potomac, Va.), Cierra Strickland (McNamara) and Christine Weithman (Blake) were other non-senior locals on the GMU roster last season.

Jackson last season at Bullis averaged 9.5 points and made a team-high 37 three-pointers on a 21-5 team that won the ISL AA tournament title and finished 17th in the rankings. She also considered offers from Virginia Commonwealth, Towson and Stetson but settled on GMU because it was close to home and she liked the campus and down-to-earth vibe she got from the women on the team.

“I’m really excited to get in there and start working,” Jackson said, “and hopefully do great things.”