Charles Best is 16 years old and changed, he said, from a shy kid who didn’t always pay attention in school to one hungry for knowledge and looking forward to his future.

Although he always made good grades, he was neither the smartest kid in the class nor was he the loud-mouth troublemaker who didn’t even try.

No, Best was what educators at Odyssey call “the middle third,” those students who need that little extra push to reach their full potential.

In 2006, while he was still in middle school, his mother enrolled him in Odyssey.

“At first, I didn’t want to come, thinking it would be boring. But it was really fun,” said Best the other day in a break from the first week of classes. “The classes were interesting. The teachers were great.”

Five years later, the rising senior from Alpharetta is back for another six weeks.

The summer program dates back to 1972, when the Atlanta Public Schools and the Westminster Schools formed a public-private partnership, providing reading enrichment to low-income APS students. Other programs were soon introduced, including the arts, science and economics.

For many years, however, the programs seemed like “five seaworthy ships all headed in different directions,” said M.J. Thorne, Odyssey's executive director.

Then in 1994, Sandy Smith, a local attorney and one of the program’s volunteers, suggested they create a non-profit with a different charitable purpose.

Six years later, the partnership attained its non-profit status. In 2005 the program developed a new mission and curriculum that shifted the emphasis to a long-term thematic integrated course of study that would put students on “a quest for knowledge and a path to college.’’

That year the partnership also changed its name to Odyssey.

“We created an opportunity for kids who were just bumping along in school to get excited about school and improve their academic performance each year,” said Smith.

And so from 8:30 a.m. to 3 p.m. Monday through Friday, students gather for the six-week program, which is held on the campus of the Westminster Schools and costs $755,000 to run. There is no tuition charge.

“Odyssey is a great way to move the academic needle,” said Smith.

Studies show that by the end of fourth grade, low-income students are already two years behind other students, said Thorne. By the time they reach eighth grade, they are three grade levels behind in reading and math. If they reach 12th grade, they are four years behind their peers.

These educational disparities are compounded by students’ lack of summertime enrichment, when any gains made during the year can be lost through a lack of reinforcement, said Thorne.

Odyssey targets APS students in third to 12th grade who have unmet potential. It focuses on core academics, the arts and critical thinking skills. When the program was reconfigured in 2005, Thorne said that retention became a major part of its goals.

Before, Thorne said, a student might come for three weeks, learn science and never return.

“Now there are 30 rising seniors and 85 percent of them have been with us for at least two summers,” she said.

Thorne said that because retention is so high, most new students to the program are rising third graders.

In all, more than 3,000 students have benefited from the program since its inception.

Best, who recently transferred to Alpharetta High School, is among 305 students enrolled this summer. He said before coming to Odyssey five years ago, he “sometimes slacked off and didn’t really think about college.”

Now, he said, he dreams of attending Georgia Tech after graduating high school and one day becoming an engineer.

“When I came here, my favorite subject was literature,” said Best, a soft-spoken kid with a twinkle in his eye.

But he said his affection soon turned to math, though, because the teachers made it simple.

According to Thorne, getting the best teachers in front of the Odyssey classrooms is a top priority.

“The teachers we recruit are master teachers,” said Thorne.

Those teachers, 40 in all, are drawn from all over metro Atlanta and in many instances are their districts' teachers of the year, like Hilaire Anelone.

Anelone, the Atlanta Public Schools’ star teacher, has been teaching mathematics at Odyssey since the summer of 1997, when he was asked to fill in for another teacher.

“I fell in love,” he said.

In addition to teaching some of “the best kids in the city,” Anelone said he also gets to learn from some metro Atlanta's best teachers.

For instance, he said, he’s learned to set high expectations for his students and provide small doses of information to guard against losing them. And perhaps most importantly, Anelone said, he's learned, “You really can’t teach a kid if he doesn’t know you genuinely care about him.”

That kind of  concern is what made Faith Bailey want to join the program’s 70 other volunteers.

Bailey, a 17-year-old rising sophomore at Berea College, attended Odyssey during her junior and senior years of high school along with two of her siblings.

It was at Odyssey, she said, that she discovered that people cared about what she had to say and what she wanted to do with her life. Because of that, she said, she wanted to come back this summer as an intern.

Bailey, a resident of Fairburn, supervises a small group of children in Odyssey’s after-school study hall program.

“I wanted the kids to see there are positive people who want to help,” she said.