In 1985, Chris Mullin led the St. John’s basketball team to the Final Four. Last spring, he was brought in as head coach to revive his alma mater. Photograph by Michael Conroy / AP

On a Saturday in early February, the St. John’s men’s basketball team hosted the Butler Bulldogs, a Big East rival. It had snowed much of the morning, but Carnesecca Arena was packed to the rafters; among those in attendance was Lou Carnesecca, the gym’s namesake, a onetime head coach at St. John’s and a member of the Basketball Hall of Fame. Carnesecca spent the first half passing around a worn glamour shot of the team’s current coach, Chris Mullin, who played for Carnesecca at St. John’s before going to the N.B.A. Mullin became an All-Star for the Golden State Warriors and earned a spot on the famous 1992 U.S. Olympic Dream Team; he’s in the Hall of Fame, too. Among the fans that Carnesecca passed Mullin’s photo to were a pair of nuns, sitting, in their habits, just a few rows in front of the former coach. Sister Mary Mercedes and Sister Mary Terence—or Merce and Kathryn, as the thirty or so Mullin family members in the crowd called them—hadn’t been to St. John’s since 1985. They were back for the same reason they attended then: to support Chris. When he was inducted into the Hall of Fame, in 2011, he invited both women to the ceremony, and even mentioned them during his speech: “At my age, and you’ve still got two ninety-year-old nuns praying for you, you know life is very good,” he said.

Mullin may be the most beloved basketball figure in New York City. As a shaggy-haired guard, the Brooklyn native led St. John’s to the 1985 Final Four, still the brightest moment in the program’s fairly bright history. He was brought back to Queens last spring to revive his alma mater, which has made just two N.C.A.A. tournaments in the past ten years. The challenges in his first year have been numerous: twenty-two losses, and a 1–16 record in Big East play, including the eventual loss to Butler. But on that cold day in February, even when the Bulldogs’ lead stretched to forty-one points, and other fans started to disperse, Merce and Kathryn stayed put. “The team will be good eventually,” Sister Mercedes said. She has confidence in Chris. “With the support of Lou Carnesecca, he’ll make it,” she told me. The pair have trouble walking on icy surfaces, but they wanted to be there for what was one of the team’s final home games this season. A niece had given them a lift from the Sisters of Mercy assisted-living facility in Queens that they both now call home.

That was where I visited them, in December, to talk about the return of Mullin, who is also Sister Terence’s nephew. (She is the third of ten children; her younger brother, Rod, was Chris’s father.) Sister Mercedes is eighty-eight; Sister Terence will turn ninety-five this year. The two have been best friends since the early nineteen-fifties, when they met at the Angel Guardian Home, a Catholic orphanage, in Bay Ridge. Sister Terence was a licensed practical nurse, then taking care of the dozens of one- and two-year-olds who lived in the home. Sister Mercedes facilitated the adoption process. “She spoiled most of the children,” Sister Terence told me.

On most nights and weekends after they first became friends, the sisters would leave the convent and spend time with each other’s families, visiting Sister Terence’s mother in Flatbush or enjoying a Sunday dinner of spaghetti with Sister Mercedes’ family in the Rockaways. “At that time, all of our relatives were having children,” Sister Mercedes said. That included Rod’s burgeoning family. “Every time his wife, Eileen, had a baby, we went to their house on Troy Avenue to see them,” Sister Mercedes said. “We saw Chris when he was born, and we watched him and his four siblings grow up.”

Eventually, the dinners migrated to the Mullins’ three-bedroom stand-alone house in Brooklyn’s Flatlands neighborhood. Meals often had to wait until the back-yard basketball games between Chris and his brothers had finished—and those games sometimes continued in their shared bedroom. “You could never hear if you were in the living room of their home,” Sister Terence said. “There’d be at least one hoop active, or they’d be arguing and slapping the backboard. God help their neighbors—they had the patience of Job.” She and Sister Mercedes were not always so patient. “Whenever we were visiting and all the boys would come home,” she said, “we’d excuse ourselves and say we didn’t realize the time. Baloney. We just didn’t want to be there for the racket.”

She thought Chris, like his father, would become a customs inspector at John F. Kennedy International Airport—“Chris always visited whenever someone interesting came into customs”—but the sisters soon saw the passion he had for the game. They decided they would be there to cheer him on. From his C.Y.O. league days at St. Thomas Aquinas—the green-tiled gym, which Chris had a key to, was just two blocks from his home—to his games at Power Memorial Academy and Xaverian High School, they never missed a chance to see him play. When Mullin famously decided to spurn some of the country’s biggest college-basketball programs, including Duke—“Coach Mike Krzyzewski came to the house with a bouquet of flowers for Eileen and begged her to send Chris to Duke,” Sister Mercedes recalled—and enrolled in St. John’s, the sisters followed. “We went to every St. John’s home game,” his aunt told me. Saturday games were their favorites: they would attend Mass at the school’s chapel and, following what was usually a St. John’s win, visit Chris in the locker room. The whole team would then go to Dante Restaurant, an Italian restaurant that Carnesecca loved, for post-game eggplant parm. “Theirs was the best,” Sister Mercedes explained.

Even when Chris went to the 1992 Olympics, in Barcelona, the sisters were able to help by watching the family dog while he was away. Eight years before, when Chris made his first Olympic appearance, in Los Angeles, they were there—according to Sister Mercedes, at least fifty friends and family crashed in the same house during those games. “Sister Terence went to the bathroom one night, and there were all these people sleeping on the floor,” she said. Among Chris’s teammates was Patrick Ewing, then with the Georgetown Hoyas, another Big East team. Sister Mercedes told me that Chris’s grandmother confronted Ewing in an elevator, at the team’s practice facility, and pleaded with him to be good to her grandson.

When Mullin was introduced as the new head coach of St. John’s, last April, the sisters were noticeably absent. “It’s hard now—I can’t drive a car anymore, so, unless someone takes us, we have no way of getting to St. John’s,” Sister Mercedes said. They couldn’t get a ride from one of the many Mullin nieces or nephews that day. “He was surprised we weren’t there,” she added. “He always looks for the nuns. I guess that’s for prayers so they win!”

Midway through the second half against Butler, it was clear even to the optimistic sisters that St. John’s would not stage a comeback. They didn’t mind, though. They enjoyed watching Chris back on the St. John’s bench. “We heard he is getting some really good players next year,” Sister Mercedes said, “so I hope the team doesn’t get too discouraged.” After the game, they were going to visit Chris in the locker room, just as they had countless times before. Dante Restaurant is no longer open, so they planned to go to a relative’s house for the post-game family meal. “We always liked watching Chris play basketball,” Sister Mercedes said. “But also there isn’t a lot that happens at a convent at night, so, if you could go to a game, that was one of the things we enjoyed.”