Inside look at historic US Open semifinal battle between Frances Tiafoe-Taylor Fritz

Friday’s U.S. Open semifinal between Frances Tiafoe and Taylor Fritz will be an all-American affair.

Fritz vs. Big Foe marks the first time since 2005 that a Grand Slam semi will feature not one, but two American men.

Tiafoe and Fritz are countrymen and close friends. But that friendship doesn’t make them clones, on or off the court.

They’re not the same, don’t have the same game, and couldn’t have more different personalities.

Fritz’s game is about that serve. He’s a big hitter who has worked to improve his movement.

Tiafoe is a plus athlete who can redirect his foe’s power to his advantage.

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In boxing, they say styles make fights. Well, this fight should be plenty stylish.

“Frances is a better mover, covers the court, better athlete,” former great John McEnroe told The Post. “Taylor’s a better striker, one of the best ball-strikers I’ve seen in the last 10 years. Hits an incredible ball.

“So to me, the key would be Taylor dictating points with his groundstrokes, pushing them right into serve, and Frances being able to get him on the run, then be able to use his own athletic ability. That would be the key thing. And the last part would be: Frances needs to serve at a higher consistency, better first serve percentage than he has.”

The difference is not just in play but also in persona.

Big Foe has a big personality. He’s more boisterous and outgoing.

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The child of Sierra Leone immigrants, his father served as the maintenance worker at a tennis center he lived in. Fritz is a laid-back Californian whose mother — a former top 10 player — is an heir to the Macy’s fortune.

“As personalities, you can’t meet two more extreme. He’s video game, never leave the room, goofball. I’m loud and obnoxious at times,” Tiafoe said. “But he’s also very funny. He’s got that dry humor, smart ass, but that’s why we like each other because we’re so different, and that’s why we get along so well. As competitors, we’re alike. Hate to lose, we battle hard. But personalities, we are very different.

“Taylor and I had a conversation about being [Nos.] 1, 2 Americans for a very long time. I remember we were sitting on a plane some years ago — and he’s [a] pretty to-himself kind of dude — and he’s, like, ‘Bro, I think me and you are going to be 1, 2 Americans and leading the way.’ Coming from him, I was like, ‘Dang dude, 6 a.m., I’m pretty tired. But let’s do it. Why not?’

“Now, it’s great that we get to compete against each other in such a big match. I’m happy for him. I know he’s happy for me. Let the best man win come Friday. It’s going to be epic. Popcorn, do what you’ve got to do. It’s going to be a fun one come Friday.”

Fritz has history on his side at 6-1 against Tiafoe, including a win in their only Grand Slam meeting at the 2022 Australian Open. But under the lights on Ashe, when Tiafoe is at his best, is another story.

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“It’s different on Ashe, man. It’s different,” Tiafoe said. “He’s tough, man. He’s a tough player. He plays great from both sides, has a great serve, he’s moving much better now. It’s going to be tough.”

Fritz — a great hardcourt player — didn’t drop a set through his first three matches, then beat Casper Ruud and Alexander Zverev in four sets, winning 81 percent of his first-serve points against the latter.

But now he’s improved his return game and movement to accentuate that big serve. He should have easier service games against Tiafoe, who has struggled in this series.

It could have the makings of a U.S. rivalry like Andre Agassi vs. Pete Sampras.

“Back in the day, the Andre fans, if Pete hit an amazing shot, Andre fans will still give him some love and vice versa. So I think that will be the case. I hope that’s the case. But I think the atmosphere is gonna be amazing,” USTA Player Development GM Martin Blackman told The Post.

So which one is Sampras, and which is Agassi?

“Pete was much more introverted, so Taylor’s a little more introverted. And Andre’s more extroverted. That’s as far as I’ll go with that one.”

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