Chase Thompson, middle, poses for a photo with his grandparents, Bill and Judy French and Joyce and Richard Thompson (from left), after signing a letter of intent to play at Clemson during a ceremony at Alexandria Area High School in Alexandria, Minn., on Wednesday. Both grandfathers played basketball. (Leila Navidi/The Minnesota Star Tribune)

ALEXANDRIA, MINN. – Decades before three-pointers entered the world of high school basketball, Chase Thompson’s grandfathers competed in the hardwood sport that’s ingrained in his DNA.

Thompson, 18, officially signed his scholarship acceptance and financial package documents to play basketball at Clemson University on Wednesday inside the gymnasium at Alexandria Area High School. He sat front and center in a long row of tables, flanked by 17 other student-athletes committing to college teams on the first day of the NCAA’s early signing period, when all high school seniors in sports other than football can begin signing with Division I and Division II athletic programs.

The brief ceremony on a rainy November morning before the first school bell rang marked a special moment for Thompson’s family, full of pride but no surprise.

“He was the type of person that when we were traveling to and from tournaments, he was on YouTube studying basketball moves or studying film of another player,” Thompson’s mom, Kyla, said. “He thrives to get better. So I’m not surprised of this ... because he’s worked hard, he’s earned where he has gotten, where he’s going, and we’re just excited to see what the future holds for him.”

It’s as if Thompson was destined to be a basketball star when looking at the legacy of players in his family. Beginning with his grandfathers, then his dad, who still plays three days a week, and then his big brother.

“It runs in the family,” his father, Kyle, said. “There’s a lot of basketball.”

Treyton Thompson, 22, plays at Stetson University, where he helped the team win its conference last year and reach the NCAA tournament for the first time in school history. He’s 7-foot and left Alexandria after his sophomore year to play prep school ball before joining the Gophers.

Like his brother, Chase Thompson towers above classmates and most competition at 6-8. But he’s incredibly humble, and he doesn’t hesitate to show his appreciation to those who helped him arrive at this moment.

“I definitely learned a lot of life lessons from both my grandparents and then obviously my dad played growing up too,” he said. “My brother, he was just a huge role model growing up. He kind of paved the way. I got to see it firsthand, you know, throughout his experience, throughout his recruiting, and then just kind of transferred from him to me, and now I’m here.

“My parents are super supportive. They’re at every game, and they go to Treyton’s games down in Florida, too,” he continued. “Last year, during the state tournament for basketball, they went to my two games, flew to New York, watched his March Madness game and then flew back that Saturday morning. They’re crazy. They travel everywhere, and they love watching me play.”

Chase Thompson, right, and his father Kyle, left, sign a letter of intent for Chase to play basketball at Clemson during a ceremony at Alexandria Area High School in Alexandria, Minn., on Wednesday. (Leila Navidi/The Minnesota Star Tribune)

The senior will now pivot all of his attention to football. As one of the most talented quarterbacks in the state, he’s leading Alexandria in its quest for the Class 5A championship. The football team competes in the state semifinals this weekend at U.S. Bank Stadium.

Football was a surprise for the Thompsons. They’re a basketball family.

“Two number one basketball players in one family. That’s something,” said grandpa Richard Thompson, 79, at the signing ceremony Wednesday.

The height comes from Richard and Kyle. Both played basketball at Glenwood. Thompson’s other grandpa, Bill French, stood at 6-5 on the court.

“I still have a couple records, but we don’t talk too much about that,” French said.

French, 83, graduated from Sauk Rapids in 1959, when he set the school record for most points in a game at 37 and the highest points average in a season at 24, and “they didn’t have three-pointers, you know,” he said.

“He’s put in so much effort since the fourth grade and just playing all year round, especially in basketball, this football was a surprise,” French said of his grandson.

Richard Thompson added: “We thought he was going to be basketball and baseball. He went to a football camp when he was a 10th-grader. He loved it so much that he forgot about baseball.”

No matter the sport, their grandson has their unending support.

“It feels great. Just very grateful that I still have all four grandparents. They get to come watch me play basketball all the time [and] play football,” Thompson said. “My goal is for them to be able to watch me play in college. Hopefully that can happen.”