Rieser and Young ended up watching the entire Gauchos scrimmage.
"She was doing some things . . . that I haven't seen many girls' basketball players do," Rieser said.
At the time, Rieser said, he was merely a basketball fan admiring a great player who happened to be from Philadelphia. He said he had no clue that he eventually would get the opportunity to coach Copper.
Maybe Copper's jaw-dropping athletic ability would have carried her teams to championships regardless of whether she left Girard College, the boarding school she attended from first to 10th grade. Maybe she still would have received a scholarship to play for legendary coach Vivian Stringer at Rutgers.
That alternative story will never be written, though, because two months after the Exposure Championships, Girard College lost its coach and dropped out of the Bicentennial League. Copper decided her own fate by transferring to Prep Charter, "a couple bus rides" from her North Philadelphia home.
Two Public League championships and state semifinal appearances later, she is The Inquirer's Southeastern Pennsylvania girls' player of the year.
Copper flourished in captaining one of the city's youngest teams to a 28-4 record. As a 6-foot-2 guard doubling as a forward, she averaged 21.6 points and 16 rebounds.
"She literally put us on her back and carried us to the state semifinal game," Rieser said.
It took a year before the coach could develop his prized player into an alpha dog. During the 2010-11 season, the Huskies' four seniors, including Young, led the team in warmup stretches before practice.
At the second practice this season, Rieser pulled Copper aside from the three sophomores and one freshman who joined her in the starting lineup.
"That's your job now," he told her. "You have to lead them."
Copper understood: "It was time."
During the Huskies' challenging nonleague schedule, the sight of Copper taking command of huddles, putting a hand on a teammate's shoulder, or whispering in an ear became common.
"She helps you get better," sophomore co-captain Indiah Cauley said. "People really look up to her."
And when games started flying by faster than any 14- or 15-year-old could comprehend, Copper made sure the ball found her reliable hands. The mid-range game she learned at Prep Charter, Rieser said, "opened up everything."
If becoming a college star was Copper's goal, she could not simply rely on her athleticism to overwhelm opponents. She had to recognize that "basketball is a game of footwork," Rieser explained.
So first came the chair drill: dribbling through chairs set up at the three-point line, elbow and low block. Then the fade drill: setting screens and releasing to catch and shoot.
Day after day, Rieser sharpened the skills Copper already possessed - natural quickness and jumping ability - and added new moves - a pull-up, a step-through, a pump fake - to her arsenal.
"She thirsts for the knowledge of the game," the coach said. "She wants to know, 'What else can I do to get better?' "
As the season wore on, Copper kept getting better. She put up 34 points and 22 rebounds against Washington Township (N.J.) on Dec. 28, 40 and 22 against Freire Charter on Feb. 4, and 41 and 15 in a season-ending, PIAA Class AAA semifinal loss to Lancaster Catholic on March 21.
In the wee hours of an early-February night, she woke up to a phone call. It was Rieser, telling her she had been named a McDonald's All-American.
"I thought I was dreaming," Copper said.
On Wednesday night, Copper played with the rest of the 23 best players in the country at the All-American game in Chicago.
No, it was not a dream. This is Kahleah Copper's reality.
Contact staff writer Brian Kotloff at email@example.com.