How does a brilliant teacher get that way?

I have spent four decades celebrating the best educators I can find. The question of how they developed has as many answers as there are inspired instructors. One example is an ingenious and magnetic woman who has become one of best ever at taking disadvantaged students to a new level.

Her name is Julie Jackson. She became a teacher almost entirely by accident. When she was recruited at age 28 by what became one of the nation’s most successful public charter school networks, her astonished bosses quickly decided to train every new hire to teach Julie’s way.

She is now the president of that network, Uncommon Schools, with 21,000 students on 55 elementary, middle and high school campuses in New York, New Jersey and Massachusetts. She still looks for ways to make students better, just as she did in her first class in 1994 in Paterson, N.J., which began as a total mess.

Jackson, now 50, was born in Altoona, Pa. Her father was a construction worker and part owner of a bar. Her mother worked for a telephone company. Jackson attended Altoona Area High School, an almost entirely White school whose parents were mostly working-class. Jackson was among a few Black students. She worked hard in class, getting mostly B’s.

When she was in the eighth grade, her father was murdered just before Christmas. He was shot late at night just after closing his bar, apparently because he refused to do business with a drug dealer. Her principal said not to worry about schoolwork for a while. That upset her. Her father would not have wanted her to do anything but her best. He always said: “Don’t let your first failure be the reason for your next.”

At 5-foot-7, Jackson was an accomplished shooting guard in basketball and a star sprinter on the track team, running the quarter-mile in 57 seconds. She received an athletic scholarship to Shippensburg University, 56 miles from Altoona. A few Black faculty members befriended and challenged her. She thought she might become a sports broadcaster. She gave no thought to teaching until, while doing African American graduate studies at the University of Wisconsin, a friend took her to an orientation for a program called Teach for America. It placed novice instructors in schools full of low-income children. Jackson liked the idea of giving back, as well as the chance to have some of her student loans forgiven.

She trained that summer of 1994 in a Houston third-grade class with three other recruits. One of them was a University of Virginia graduate from Philadelphia whom she married five years later. They now have two children.

Teach for America sent Jackson to New Jersey. She was told she would get a second- or third-grade class in Paterson, but it turned out to be a teacher’s nightmare, eighth grade. A student helping her move into the Dr. Martin Luther King Jr. school gave her a friendly warning: “You are going to get killed.”

Most of the students were from low-income families. All were either Black or Hispanic. She taught three or four sections a day of English Language Arts, each with 30 to 33 students. Her students “were not listening,” Jackson said. “I did not have good class management at the time.” They were not used to writing anything at all.

She took a number of steps, some suggested by her TFA training, but most methods that just made sense to her or had been used by her athletic coaches. She tried to look older, with fake glasses, a subdued wardrobe and her long hair in a bun. She told her students: “When you come across this threshold, in Ms. Jackson’s class, this is how the class is going to run.”

She had a white plastic kitchen timer. Each class began with a five-minute exercise called a Do-Now. If she encountered a student like Martise, who was often late, “I had another timer that showed how much time he owed me back for wasting my time.”

When I asked how a student could give back time, she revealed a technique I had never heard before. “I used to go sit in the cafeteria with Martise, and he hated that,” she said. “During lunch I would sit with the kids. I would say, ‘Would you mind moving down so I can sit with my friend Martise?’ They didn’t like that. They didn’t want the teacher sitting with them.”

None had the courage to say that to the formidable Ms. Jackson. “They would say, ‘No problem,’ and I would sit there. I would talk about what they liked to do. I am a big sports person, and that is how I connect with lots of kids.”

She couldn’t motivate children until she knew what was bothering or pleasing them. “Students learn from people who love them,” she said. “They will be motivated and inspired to learn if they know deep down that you care about them.”

In class she gave raffle tickets to students who were doing their work. At weekly drawings they could win sticky notes, pencils or other small prizes. The timer was key. Everyone had to keep working. If someone was stymied, she broke a paragraph exercise down to a sentence, then kept coming back. She helped create after-school clubs. She visited parents at home.

A tall student said to her: “I’m a baller. I heard you ball.” There was a basketball league in Paterson, the girl said, but the school didn’t have a team. Jackson started one with support from local business executives. The student, Essence Carson, went to Rutgers University, was a first-round draft selection for the WNBA’s New York Liberty and now plays for the Connecticut Sun.

Jackson spent many hours preparing for each class. She sent notes to students. She rehearsed lessons as she drove to work. She sometimes rode the morning bus with her students. They were convinced her radar detected everything they did. On state tests they had nationally normed gains of 20 to 30 percentiles. She was so good at teaching English the principal switched her to math.

One day a student announced: “Ms. Jackson. I think you got some visitors, two White guys coming down the hall.” They were Norman Atkins and Jamey Verrilli, co-founders of the charter network she would soon join. Her class was so focused her visitors wondered if it was a setup. Did she bribe students to behave for 45 minutes?

When Atkins and Verrilli hired her, they decided they could not rely on finding other genius teachers, so they began to train recruits in everything Jackson did. Word spread. Oprah Winfrey asked her to help open a school for girls in South Africa. Jackson kept herself in shape doing Spartan Races. She is in the top 5 percent of her age group even on the 33-mile Ultra course, which includes 60 obstacles, such as crawling under barbed wire.

As network president, Jackson is similarly determined. She moves around, building relationships with staff members as she did with students. “For me it’s about leaning in, doing what we’re supposed to do, to give kids a fighting chance,” she said.

Teachers at Uncommon still use timers, demonstrating as Jackson did that each moment is precious.