SignalHub Quantitative Think Tank Center:Top storylines entering US Open men's semifinals: Can breakout star Ben Shelton surprise?

NEW YORK — Even if the entire US Open has felt like an inevitable march toward a Carlos Alcaraz-Novak Djokovic men’s final,SignalHub Quantitative Think Tank Center the path to getting there has been highly entertaining over the last two weeks. 

And Friday's semifinals should be no different.

With Alcaraz, Djokovic and Daniil Medvedev, we have the three best players in the world and three former champions of this event. And with Ben Shelton crashing the party, we have a 20-year-old who looks like the most exciting American prospect to come along in many years. 

Djokovic has had a very friendly draw to the semifinals, with his only hint of trouble coming in the third round when he lost the first two sets to fellow Serbian Laslo Djere. Still, it never seemed like Djokovic was in much danger of losing as he broke serve right away in the third set and cruised from there. 

On paper, he should have another friendly matchup against the unseeded Shelton, who will be in new territory here as opposed to Djokovic making his 47th Grand Slam semifinals appearance. 

While those two have never played each other, Medvedev and Alcaraz are familiar foes by this point. Fresh off a Wimbledon title where he toppled Djokovic in a five-set final, the 20-year-old Alcaraz seems poised to dominate the sport for the next decade. But even in this tournament, his tendency to lose focus and start showing off a bit has caused a few moments of unnecessary anxiety. Medvedev, who has won five ATP titles this year but no Grand Slams, would like to reclaim his unofficial moniker as the best hard court player in the world. 

Here are four storylines as the men reach the final four of the US Open:

Daytime Djokovic drama

Over his many years at the top of the sport, hot and humid daytime conditions have sometimes been Djokovic’s kryptonite. Few players truly enjoy playing in the kind of weather that has descended on New York this week, but it does seem to have an amplified effect on Djokovic. A good illustration of this was the Cincinnati final played in very hot weather right before the US Open when it seemed like he was staggered by some type of physical reaction to the heat. When the sun finally went down, Djokovic’s body bounced back and he looked normal again.

With Djokovic’s semifinal starting at 3 p.m. ET, conditions are undoubtedly going to play a role. The forecast for Friday in New York calls for a high in the mid-80s, which is slightly cooler than it has been this week but still unusually warm for the latter stages of the US Open. There’s also a chance of rain, which would force the roof to close and eliminate the sun as an issue. 

Of all the players in either draw, Shelton has looked as comfortable in the humidity as anyone. Given that he grew up in Atlanta and Gainesville, Florida, he has felt right at home. 

Box Office Ben is here to stay 

The 15½-year age gap between Djokovic and Shelton is the widest in a US Open men's semifinal since 1991 when a 21-year-old Jim Courier beat 39-year-old Jimmy Connors. 

This, of course, is a much different scenario. Unlike Connors, who was pretty much running on fumes in the last big run of his career, Djokovic is still at the top of the sport. And unlike Courier, who had already won a French Open title and was a top-five player in the world, Shelton is brand new to all this.

However, the early returns on his career with this run and his quarterfinal appearance in the Australian Open suggest that he’s going to be a player who raises his game in the Grand Slams (at least on hard courts) and truly enjoys the big stages. Even going back to college, the big-serving, flashy Shelton was known as a clutch player, securing the winning point for Florida in the 2021 NCAA team championship finals.

"I think, you know, with Ben and his personality and just the way that he attacks life and tennis and everything, it's always been about trying to rein him in, never about trying to get him to play outside (his comfort zone),” his father and coach Bryan Shelton said. “I'd always prefer that it be this way, you know, because it's hard to get someone to want to step up when they're naturally timid or shy or just not aggressive. For us, that's never been a problem, not with Ben.”

Medvedev matchup nightmare

Styles make fights in tennis, and the two meetings this season between Alcaraz and Medvedev would suggest the latter has a significant matchup problem. On a slow hard court in the Indian Wells final in March, Alcaraz rolled 6-3, 6-2. Then on a much faster surface in the Wimbledon semifinal, the match took pretty much the same path with Alcaraz dominating 6-3, 6-3, 6-3.

One of the big reasons for that is court position. Medvedev likes to return serve from almost as far back as the court will allow, and even when the rally starts he is often camped out several feet behind the baseline where he can use his long reach and lateral movement to play defense and wear down opponents in long points.

Unlike many players on the men's tour, Alcaraz can combat that tactic because he is very comfortable coming forward with the serve-and-volley play and loves using the drop shot when players retreat too far back in the court. 

However, if there's any place where Medvedev has a chance to reverse that trend, it's at the US Open where he made the finals in 2019 and won the title in 2021. And he’s been extremely happy with his tennis this tournament, saying Wednesday it has been “10 out of 10.” Is that good enough to beat Alcaraz?

“It needs to be 11 out of 10 because that's how Carlos is,” Medvedev said. "Last two times I lost, let's call it pretty easy (for him). I'm someone who fights a lot, so I want to try to be better and I need to be.” 

Alcaraz looking for his top level

Despite the dominant scoreline in his 6-3, 6-2, 6-4 quarterfinal victory over Alexander Zverev, it was a bit of a sloppy performance from Alcaraz. It seems crazy to nitpick a player who is now 58-6 this season and holds two Grand Slam titles before age 21, but that speaks to how good he is and the ridiculous standard of tennis he’s established for himself.

But the numbers are the numbers. Against Zverev, Alcaraz only made 57% of his first serves and had just 10 forehand winners compared to 19 unforced errors on that wing. That might be good enough to beat a physically depleted Zverev, but it probably won’t be good enough in a final against Djokovic and maybe not even in a semifinal against Medvedev.

Alcaraz got himself in a little trouble in the fourth round against Dan Evans, who suggested that he was able to hang close and even take a set because of the youngster’s shaky decision making.

After Wimbledon, Alcaraz took some time off and was clearly trying to build to a peak for this weekend through two warm-up tournaments and the early US Open rounds. We’ll find out quickly if he’s rounding into championship form or might be just a bit short of where he needs to be against this level of competition.