"The other kids are like a sponge to him," said St. Augustine coach Bill Ward, whose team should be among the best in South Jersey this season. "He's a class act."
Clark was a three-time Maryland Independent Schools state champion and a two-time National Preps champion. He went 138-15 in three seasons at McDonough, a prestigious boarding school known for its national-caliber wrestling program.
"That was the best place for me at the time," said Clark, who also considered St. Augustine and Blair Academy, a boarding school in North Jersey with a big-time wrestling program, after finishing the eighth grade at St. Mary's School in Williamstown.
At McDonough, Clark developed into one of the country's best high school wrestlers. He is ranked fourth in the nation by InterMat at 152 pounds.
Ward said Clark is "at the same level" as 2013 South Plainfield graduate Anthony Ashnault, who finished his high school career in March with a 170-0 record and four state titles.
"He can beat anybody in the country," Ward said of Clark.
Ward acknowledged that "there's no such thing as a sure thing" when it comes to winning a state title. But the coach said Clark looms as a clear favorite in his weight class.
"It's funny. You watch him, and he's always scoring," Ward said of Clark's wrestling style. "He's so methodical, so athletic. He does all the little things right. You don't even realize it, and he's got 10 points."
Clark said he regards himself as a smart, sound wrestler.
"I'm not the strongest guy, not the fastest guy," Clark said. "I'm all technique. I'm not sloppy."
Clark said it was "tough" to live away from home as a high school student, especially in his freshman year.
"I had to learn to do my own wash, be responsible for myself," Clark said. "That's tough when you're 15."
Clark said he wanted to be at home for this school year because he plans to spend the next four or five years attending the University of North Carolina. He signed with the Tar Heels on a wrestling scholarship in large part because of his relationship with assistant coach Cary Kolat.
"I knew I would be away again, and I wanted to spend time with my family," said Clark, who lives in Washington Township with his mother and father as well as his brother Nick, a sophomore wrestler for St. Augustine, and younger sister Zoe.
Jack Clark said he had another motivation for returning home: the chance to win a state title in New Jersey.
"Ever since I was little, I've always gone to the states in Atlantic City," Clark said of the three-day event in Boardwalk Hall. "Even in high school, our season would end a week earlier and I would always go. I always dreamed about winning a state title in my home state.
"Now, I have my chance."
Under NJSIAA transfer rules, Clark must sit out the first 30 days of the season because his family did not change residences. He will be eligible to compete in mid-January.
In the meantime, Clark said he will work hard in the wrestling room, stay sharp through outside competition, and try to make the most of his senior year.
"I love it here," Clark said, standing outside the wrestling room in the basement of St. Augustine's athletic complex. "It feels like I've been here for three years."