As Shintaro Mochizuki reminds us, this is the time of year for surprises and Cinderellas

“The mighty Mochizuki has done it again!” one of the commentators calling the ATP tournament in Tokyo cried on Friday night, as local favorite Shintaro Mochizuki won his second straight three-set thriller to reach the semifinals.

“Mighty” in the sentence above was something of an ironic tribute. Mochizuki is a skinny, 5-foot-9, 20-year-old who was ranked 215th in the world at the start of last week. On court, he’s happy-go-lucky rather than intimidating; he celebrates his winning shots with a grin of infectious delight—along with a fist-pump or three.

But Mochizuki was indeed mighty for much of this week. He won his first-ever ATP-level match in the opening round; came back to upset top seed Taylor Fritz in a third-set tiebreaker, after losing the first set 6-0; and followed that up with another narrow win over Alexei Popyrin, before losing in the semis to Aslan Karatsev. He did it with a speedy, exciting, forward-moving, shot-maker’s brand of tennis.

While Mochizuki may have been a Cinderella story in Tokyo, he wasn’t a total unknown before this week. He has trained at the IMG Academy in Bradenton, Fla., since he was 12, and he won the Wimbledon boys’ title, in a field that included Carlos Alcaraz, in 2019. Perhaps because of his size, Mochizuki has struggled to make the transition to the pros; it took him nine tries to record his first ATP match win.

Now that he has made a name for himself, we come to the inevitable next question: Will he be a player for all seasons? Or just a legend of the fall?

As the latter phrase implies, this is the time of year for surprises and Cinderellas. The Grand Slam season is over, which means these last swings through Asia and Europe don’t serve as preparation for a toweringly important event. They also don’t give us the weekly jockeying for pole position that happens during the lead-ups to the majors. The tours’ year-end finals do provide incentive for second-tier players to finish in the Top 8, but the big names have already qualified. That means they play less, and when they do play, they’re often just a little less focused.

That can leave room for a long-shot like Mochizuki. But a legend of the fall is usually not that big a shock. He or she is typically a player who, during the Slam season, resides on a plane just below the elite. No. 19 Hubert Hurkacz winning in Shanghai last week, for example. Veronika Kudermetova, also No. 19 at the time, winning in Tokyo the week before that. Adrian Mannarino in Astana, Maria Sakkari in Guadalajara, Karen Khachanov in Zhuhai in September. Players who can shine on the world’s second-biggest stages, but not the biggest.

Khachanov was already a legend of another fall before this season. In November 2018, at 22, he straight-stetted Novak Djokovic in the final of the Paris Masters in Bercy to move to No. 11 in the world. The Russian looked ready to climb higher, but he never did. Instead, he failed to win another title of any sort for five years, and he has lost all eight of his matches with Djokovic since.

Speaking of Bercy and its legends, a young Jo-Wilfried Tsonga won there in 2008, then didn’t win another Masters event for six years. Jack Sock made a miracle run to the title on the same indoor court in 2017, then never won another tournament. And David Ferrer won his only Masters crown there in 2013. Ferrer was more than just a fall player, of course—he made the semis or better at all four majors—but Bercy remained his biggest win.

The women’s equivalent to Khachanov may be Caroline Garcia. In 2017, she soared to two big Asian-swing wins in Wuhan and Beijing, and rose to No. 4 in the world. As with Khachanov, the talented Frenchwoman finally seemed ready to fulfill the potential that Andy Murray had seen in her years before. But it wasn’t to be, at least not yet. It would be five years before Garcia would win a comparable event, in Cincinnati, and then close 2023 with the ultimate fall achievement, a win at the WTA Finals in Fort Worth last November.

I don’t think less of these players because they don’t win Slams. Rather, their records make me think more of the players who do, the special ones who can find their best when history is on the line. On the men’s side especially, it’s only when the stakes are slightly lower that the rest of the tour has a chance. Even the fall’s most important tournaments, the year-end finals, rarely serve as a springboard to major success. Over the past decade, Agnieszka Radwanska, Dominika Cibulkova, Elina Svitolina, Grigor Dimitrov, Alexander Zverev, and Stefanos Tsitsipas have all won their tour’s season-enders, but none have gone on to do the same at a Slam.

What does that mean for the mighty Mochizuki going forward? Or recent winners like Kudermetova and Hurkacz and Sakkari, for that matter? Only that it’s impossible to tell how well players will do during the Slam season based on how they do when that season is over. All we can say is that the exciting young Japanese player is a fun one to watch—and that’s all we can ask from this time of year.