Marylander Frances Tiafoe, who plays Friday in US Open semifinal, offers hope for present and future of U.S. men’s tennis

Frances Tiafoe’s run to the U.S. Open semifinals is, first and foremost, about Tiafoe himself, a 24-year-old from Riverdale in Prince George’s County who took up tennis because his father was a janitor at a junior training center, a player who never won a match past the fourth round at a Grand Slam tournament until now, who owns one career ATP title and a sub-.500 career record, and whose ranking ranged from 24 to 74 over the past two seasons. “A Cinderella story,” to use his phrase. Tiafoe’s tale — which already includes a victory over 22-time Grand Slam champion Rafael Nadal along the way to Friday’s matchup against No. 3 Carlos Alcaraz of Spain with a berth in the final at stake — is about so much more, too.