Men's tennis has enjoyed a decade-long golden era with only a handful of players breaking through at Grand Slams. Year after year, though, we've vetted the "next big things" in the sport, a label that few in the Federer-Nadal-Djokovic age have lived up to.
But it's a new year, and with it comes another sampling of bright prospects. We won't be naive and suggest any of them will win a major this season, but if we're looking for a new set of whippersnappers to flash their talents, here are our choices:
Many consider Tiafoe, a 17-year-old who is already ranked in the world's top 200, to be the future of American men's tennis. Jay Z signed Tiafoe to the musician's boutique sports management agency, Roc Nation Sports, in part because the teenager's backstory holds such a strong appeal to him.
Never before had the agency represented a tennis player, but here was Tifaoe, whose parents had emigrated from Sierra Leone in West Africa and whose father was head of maintenance at a tennis facility in Maryland. During the day, Tiafoe and his brother taught themselves tennis while their father worked, and at night they slept in a storage room on a massage table.
Tiafoe's talent abounds, as he demonstrated at the 2015 Winston-Salem Open, where he came through qualifying to win his first match on the main circuit.
A Swedish teenager of Ethiopian heritage whose father was a fine marathon runner, Ymer has looked to Muhammad Ali and Mike Tyson for inspiration because of their "killer instinct." Such a spirited, combative approach to his tennis helped Ymer achieve the rare feat of qualifying for all four Grand Slam tournaments in the same year last season. Unfortunately for Ymer, he lost in the opening round of all those majors, but expect him to make a cameo, or four, at the majors in 2016.
Ranked No. 51, Chung was voted by his peers the most improved player of 2015. He took up tennis as a child only because someone had suggested the sport would improve his less-than-stellar eyesight. Wearing sports prescription glasses, Chung is seeing the ball as clearly as anyone. Highlights in 2015 included winning four Challenger-level tournaments and making the quarterfinals of the ATP event in Shenzhen. Goran Ivanisevic predicts Chung, 19, will be a top-10 player in the near future.
The highest-ranked teenager in the world, Coric ended 2015 at No. 44 in the standings, and he will be hoping that his new partnership with Andy Murray's former coach, Miles Maclagan, will propel him to greater heights in the new season.
One thing Coric, 19, doesn't lack is self-confidence. Tattooed on the inside of one of his biceps are the words: "There's nothing worse in this life than being ordinary." And he has already beaten half of the Big Four, with a victory over Rafael Nadal in Basel in 2014 and against Murray at the 2015 Dubai Championships.
When Edmund took a two-set lead against Belgium's David Goffin in the opening match of the 2015 Davis Cup final, it appeared as though the 20-year-old Briton was about to achieve something phenomenal.
Unfortunately for Edmund, it wasn't to be, and he lost in five sets. But he did enough in those first two sets to demonstrate his talent. Murray believes in Edmund so much that the two-time Slam winner made sure he was there in the crowd at the 2015 French Open, where his countryman picked up his first main-draw victory in a major.
Another of Edmund's admirers is ESPN analyst and seven-time Slam winner John McEnroe: "He's got huge upside."
Still only 18, the German was the youngest player in the top 100 at the end of 2015. The highlight reels for the season include making the semifinals in Bastad and the final eight in Washington. And no one could suggest that his run in Bastad was a fluke, as it wasn't even the first time he had make the last four of an ATP tournament. In 2004, he reached the Hamburg semifinals.
Roger Federer's endorsement of aspiring young tennis players can be seen through his choice of practice partners, and during last summer's Wimbledon, he elected to train with Fritz. Federer's inclination was right, as Fritz won the boys' singles title a month later at the US Open and finished 2015 as the top-ranked junior.
Just before Christmas, the 18-year-old Californian was named the International Tennis Federation Junior World Champion, the first American boy to win that award since Donald Young in 2005.
Fritz has a strong tennis pedigree as well. His mother, Kathy May Fritz, played in three Grand Slam quarterfinals and was ranked in the top 10, while his father, Guy, also played professionally.