Not everyone who’d like to take a private tennis lesson is a member of a private club. Ditto golf. And for other sports, finding the right person to provide private coaching is even more challenging. That’s the problem that CoachUp hopes to solve as it formally launches in Boston today.

CoachUp is an online marketplace to help connect people with private sports and fitness coaches, who have been pre-screened by the company and will be rated by the CoachUp community.

CEO and founder Jordan Fliegel claims that sports coaching (not just private) is a $3-7 billion market globally, without including fitness training.

“Private coaching is in every single sport,” he said. “It’s just most private coaches don’t have websites, they don’t know how to market their services.”

Lots of former professionals and current assistant college coaches are looking to supplement their income with private coaching, according to Fliegel, and more than 100 private coaches in Boston have already signed up for CoachUp.

“Coaches are really kind of flocking to us,” he said. “We want to get really good coaches on our site and we want to make it a really good deal for them.”

The site’s launch today extends to greater Boston, with the hope of expanding to more cities starting in the fall. The company has raised an undisclosed amount from angels, has a staff of five, and is already collecting revenue.

Fliegel played basketball at Bowdoin and then professionally in Israel, before going to business school, and has done his share of private coaching. Before starting CoachUp, he worked at Zintro, an online expertise marketplace.

“I know private coaching and I know online marketplaces,” he said.

He and his team dominated a recent Boston startup 3-on-3 basketball tournament. Whereas most startups pick hackathons or pitch sessions to demonstrate their prowess, Fliegel saw the tournament as a chance to garner some attention for CoachUp, and to demonstrate why he and his team are the right people to succeed in the sports market. They won the final game 15-0.