John Isner coolly steps to the baseline like he has thousands of times before. He bounces the ball between the legs of his 6’10” frame, and then again off the court three times with his racquet, and four times with his hand. Just as he lifts his left arm to toss the ball into the air, slightly in front of him, his racquet-wielding right arm begins its own upward motion simultaneously. The 32-year-old eventually launches toward the sky and at the last moment, Isner turns his wrist so the stringbed meets the ball, producing a devastating result.

Isner sends the ball flying as if he is wielding Thor’s hammer. The result is a blazing 138 mile-per-hour ace down the ‘T’ on a mild Houston night.

In fact, that ace on Friday in the Fayez Sarofim & Co. U.S. Men’s Clay Court Championship quarter-finals to start the fourth game of the deciding set (1-2) against defending champion Steve Johnson gave Isner 10,000 for his career. The American is one of just four players in history to enter the elite club, joining Ivo Karlovic (12,622), Roger Federer (10,463) and Goran Ivanisevic (10,131). After the history-making ace, there was a slight delay as the ball was passed to chair umpire Simon Cannavan for safekeeping.

So, how did Isner get to that milestone?

According to the World No. 9, he has made very few if any changes to his serve over the years. If it’s not broken, don’t fix it, right?

“That’s something that fortunately for me I picked up at a very early age. I’m sure if I watched footage of myself in college, my serve’s a little bit different,” Isner told ATPWorldTour.com. “But for the most part, maybe I used to move my front foot a little bit. I used to start back, take a step forward. My front foot stays still now. But the overall motion hasn’t changed a bit. I’ve seen footage of me as a freshman in high school, it’s the same serve.”

It has certainly done its job over the years. Isner has led the ATP World Tour in aces six times (2010-13, 2016-17) according to Infosys ATP Scores & Stats, striking over 1,000 aces in a season on five occasions (2010, 2012, 2015, 2016, 2017). That all led him to his 19th ace of the day against Johnson to reach the extraordinary milestone.

“I’m joining a pretty small club. It’s very cool,” Isner said. “It shows how fortunate I’ve been to be able to stay on the court for this long.”

Only one player, Karlovic, has broken the 11,000-ace mark. The Croatian has hit 12,622 aces in his career. Only the 39-year-old has hit more aces per tour-level match than Isner.

“He has a little bit different serve than me, he stays back more after it so after, he’s able to hit his forehands,” Karlovic told ATPWorldTour.com. “But it’s a pretty similar bounce, pretty similar angles. It’s also a really good serve.”

The big question is, how has Isner managed to find his best serving under the greatest of pressure? When the American clinched his maiden ATP World Tour Masters 1000 title on 1 April at the Miami Open presented by Itaú to become the oldest first-time champion at that level, he did so with an ace.

“When I feel loose, when I’m not thinking and you have a lot of adrenaline,” Isner said. “Adrenaline does everything for you… I can go through a match and not hit a serve over let’s say 132 and then I’m serving for the match and next thing I know I’m in the 140s. That’s just what it does.”

It has worked for Isner for years, and it doesn’t appear he is slowing down. The American is third on the ATP World Tour in aces so far this season.

“If I can reach 10,000,” Isner said. “Hopefully I can get to 11,000.”

All-Time ATP World Tour Aces Leaders

As part of Infosys ATP Match Stats, ATP began recording ace tallies in 1991. The tally comprises aces hit in singles main draw matches from ATP World Tour tournaments, Grand Slams and the Olympics (from 2008 on). Aces in Davis Cup competition are not included.

#NextGenATP American Taylor Fritz had never made an ATP World Tour semi-final on clay before this week. In fact, he had only played three clay-court matches combined on the ATP World Tour and the ATP Challenger Tour prior to his Houston debut. But judging by his play Friday, you wouldn’t know it.

The 20-year-old battled back from a 4-2 deficit in the deciding set to oust 2015 winner Jack Sock 6-3, 3-6, 6-4 at the Fayez Sarofim & Co. U.S. Men’s Clay Court Championship and move into the semi-finals.

“I felt like it could really go either way. I just had to get back in it,” Fritz said. “I just stayed with it and was able to come up [good] on the points that mattered.”

The victory snaps a six-match ATP World Tour quarter-final losing streak for the American, who is now 7-1 in tour-level three-set matches this year. The World No. 72, who saved two match points in the first round against another compatriot, Tim Smyczek, avenged two previous five-set losses against the third-seeded Sock, triumphing in their first FedEx ATP Head2Head meeting on clay.

Fritz is now 8-3 in tour-level matches this season and 22-6 at all levels, as he continues pursuing his maiden ATP World Tour title, after breaking through as an 18-year-old to reach the Memphis final two years ago. 

“In Memphis I think I was just playing so well for that stretch. I was just playing so far above the level I actually was at. I was playing out of my mind,” Fritz said. “Now I feel like I’m playing very within myself and playing to a level I know I can always be playing at… I’m a lot more ready. I’m a lot better of a player than I was.”

Fritz will next play one of two former American champions at this event — top-seeded John Isner (2013) or No. 6 seed Steve Johnson (2017). Fritz has lost both of his FedEx ATP Head2Head meetings against Isner, while defeating Johnson en route to his maiden ATP World Tour final at 2016 Memphis. The California native is the only player remaining who has gone the distance in each of his matches in Houston this week at the River Oaks Country Club.

Did You Know?
Fritz has now won both of his Top 20 matches this season, also beating Sam Querrey at the Delray Beach Open.

Ivo Karlovic said he was happy after his opening-round win for various reasons, including earning his first victory as a 39-year-old. Three days later, he has done a lot more than that.

The Croatian beat fourth seed Nick Kyrgios 3-6, 6-2, 6-3 Friday at the Fayez Sarofim & Co. U.S. Men’s Clay Court Championship to become the oldest player to advance to an ATP World Tour semi-final since Jimmy Connors at 1993 San Francisco. The right-hander was already the oldest quarter-finalist at Houston in the Open Era.

“It’s definitely a huge win. I lost against him every match up until now,” said Karlovic, the 2007 Houston titlist. “I’m really happy that I won today.”

Kyrgios had previously owned a 4-0 FedEx ATP Head2Head series lead against Karlovic, but the World No. 88 hit 18 aces and was not broken after his first service game in the match. The eight-time ATP World Tour champion last reached a final last year in ‘s-Hertogenbosch (l. to Muller). 

Karlovic will look to change that when he plays American Tennys Sandgren, the No. 8 seed, who came from a break down in the third set to oust Argentine Guido Pella 4-6, 7-5, 6-3 in two hours, 19 minutes to reach his first ATP World Tour semi-final. A year ago this week, Sandgren qualified for his first Tour main draw at the River Oaks Country Club.

“I was proud of myself for just sticking it out and keeping myself around and doing everything I could to keep the scoreline close,” Sandgren said. “It seemed like, from my end of the court at least, that he was doing a lot better job of handling the conditions on the clay than I was… I was really frustrated and thinking that obviously, it’s not looking good from here.”

Pella served for the match at 6-4, 5-4, but the World No. 56 broke twice in a row — his first two breaks of serve in the match — to force a decider. And from there, he broke twice more to earn his third victory of the week — Sandgren owned two tour-level wins in his career prior to this season. 

“I was watching his match a little bit today,” Karlovic said of Sandgren. “He has a really good baseline [game] and he’s a strong guy, so it will be a really difficult match.”

Did You Know?
Karlovic, who became the oldest ATP World Tour semi-finalist since Jimmy Connors at 1993 San Francisco, can become the oldest finalist since Ken Rosewall, 43, won the 1977 Hong Kong title.

Rafael Nadal has a tough task if he is to lift an 11th trophy at the Rolex Monte-Carlo Masters, with three players in the Top 10 of the ATP Rankings and also two-time former champion Novak Djokovic in his half of the draw, following the ceremony at the Atrium du Casino de Monte-Carlo on Friday. The Spanish star, who is attempting to capture his 54th clay-court crown, will need to potentially beat Dominic Thiem or Djokovic, before a possible semi-final against Grigor Dimitrov or David Goffin.

Nadal, who will meet Aljaz Bedene or a qualifier in the second round, could face Adrian Mannarino in the third round, prior to a quarter-final against 2013 and 2015 titlist Djokovic or Thiem. Nadal lost to Djokovic in the 2013 Monte-Carlo final, ending a 46-match winning streak at the tournament. The World No. 1 beat Thiem in last year’s Barcelona Open Banc Sababell and Mutua Madrid Open finals, plus also in the Roland Garros semi-finals. But Thiem did overcome Nadal in the Internazionali BNL d’Italia quarter-finals in May 2017.

“I always feel good when I am here, it is one of my favourite tournaments,” admitted Nadal, during the draw ceremony that was hosted by Zeljko Franulovic, the Tournament Director of the Rolex Monte-Carlo Masters and the 1970 champion (d. Orantes). “It’s been a love story between me and this event, the people who run the tournament. I saw this tournament on the TV before I started playing here and always wanted to do well. These sorts of tournaments help me to wake up in the morning and to train and compete with a lot of passion.”

The 31-year-old Nadal, who has a 63-4 record at the ATP World Tour Masters 1000 tournaments, has an incredible 319-35 record (.918) on clay courts according to the FedEx ATP Performance Zone. He is riding a 10-match winning streak at the event, but should he not retain the trophy Roger Federer will return to No. 1 in the ATP Rankings, for his 309th week in top spot, on 23 April.

View Monte-Carlo Singles Draw

Nadal and Djokovic have both captured a record 30 ATP World Tour Masters 1000 crowns. Monte-Carlo resident Djokovic, the ninth seed this week, will face a qualifier in his first match, before a possible second-round meeting against Filip Krajinovic or Paolo Lorenzi. Fifth seed Thiem, who opens against Andrey Rublev or Robin Haase, may then lie in wait for Djokovic in the third round.

Second seed Marin Cilic, a quarter-finalist in 2015 and 2017, will begin his quest for a second Masters 1000 title (2017 Western & Southern Open), against 2010 runner-up Fernando Verdasco or Pablo Cuevas. In the same quarter of the draw, No. 12 seed and 2015 finalist Tomas Berdych will meet Kei Nishikori in a must-see opener.

Third seed Alexander Zverev, who has a 3-2 record in the Principality, will challenge Gilles Muller or a qualifier in the second round as he bids to lift a third Masters 1000 trophy (also 2017 Rome and Rogers Cup in Montreal). Seventh seed Lucas Pouille, who advanced to his first Masters 1000 semi-final last year (l. to Ramos-Vinolas), takes on Mischa Zverev or wild card Felix Auger-Aliassime.

This time, Taylor Fritz feels as if it can last.

Two years ago, Fritz, then 18, became “The Next Big Thing” on the ATP World Tour. He reached the Memphis Open final, becoming the youngest American to make a tour-level title match since 17-year-old Michael Chang won 1989 Wembley.

Months after, Fritz made the quarter-finals of the Abierto Mexicano Telcel presentado por HSBC in Acapulco, an ATP World Tour 500 event. “The Next Big Thing” seemed like he was here to stay.

But he couldn’t produce it week after week, and his ATP Ranking, which had risen to No. 53 in August 2016, fell to No. 135 last June.

This year, Fritz is on the rise again, but he’s confident it will stay that way. His game has improved that much, he said, and he’s also learning how to win from one of most well-known coaches in tennis.

Read More: Isner Inspired By Mom’s Courage

Fritz, in addition to his regular coach David Nainkin, is working with Paul Annacone, the former coach of Pete Sampras, Roger Federer and Tim Henman. Annacone also worked with Stan Wawrinka during the grass-court swing last year.

Annacone and Fritz started working together at the BNP Paribas Open in Indian Wells last month. Fritz made the fourth round of the ATP World Tour Masters 1000 event, and he’s into the quarter-finals at this week’s Fayez Sarofim & Co. U.S. Men’s Clay Court Championship in Houston.

“I just felt like I needed someone who I thought could take my game to the next level, someone who I really respected and thought highly of,” Fritz told ATPWorldTour.com. “I think he enjoys working with me, and I think I’ve already improved so much working with him.”

Watch Fritz’s My Story

 Annacone’s attention to details has stood out to Fritz, who’s at No. 72 in the ATP Rankings this week. “Just the focus on on everything we do. The focus on not missing volleys, not missing a ball… is something that has helped me a lot,” Fritz said.

Annacone hadn’t worked with an ATP World Tour player since Wawrinka last July. But he was intrigued by Fritz, who finished as the No. 1 junior in the world in 2015.

Annacone already knew Fritz’s mother, former WTA player Kathy May, and Fritz’s agent, Matt Fawcett. He also established a good relationship with Nainkin. Annacone repeatedly praised the job Nainkin has done and stressed that Nainkin remains the main coach.

Read More: Americans Top ATP Race To Milan

For Fritz’s part, his potential and work ethic appealed to Annacone.

“He’s only 20. He has a very big game. He can do a lot of damage. He’s still, to me, is a work in progress. I love the fact that, even as a work in progress, he’s had the results he’s had already,” Annacone told ATPWorldTour.com. “I enjoy the fact that he’s not afraid to work hard. He’s enjoys hitting the gym and doing all the things he’s supposed to do.”

Annacone also particuarly likes that even on days when Fritz’s power game – his big serve and big-strike forehand – are off, the #NextGenATP American still finds ways to advance.

“My coaching philosphy is you’re really only as good as you are on your average days, so you better be able to figure stuff out, and he embraces that,” Annacone said.

Watch: What Fritz Has Learned From Annacone

For instance, in February at the Delray Beach Open, night winds were dragging the ball from side to side and up and down as Fritz faced then-World No. 12 Sam Querrey. Fritz couldn’t find his power game, but he adjusted his plan and left with one of the biggest wins of his career, a 2-6, 6-3, 7-6(4) victory against his compatriot.

Read More: Fritz: California Clutch

“It was tough to get anything on the ball. So what really started working for me was falling back, not being so aggressive and just trying to make him play as much as possible, because conditions were tough,” Fritz said.

The win was his fourth third-set tie-break victory of the year, including ATP Challenger Tour matches, and he’s added two more since then, including another this week in Houston, to improve to 6-0 in third-set tie-breaks this season.

“I have this thing I always say, ‘I don’t lose third-set tie-breaks’,” Fritz said. “It feels like I’m pretty clutch.”

More clutch play will see Fritz making his debut at the Next Gen ATP Finals, to be held 6-10 November in Milan. The 6’4” right-hander finished 11^th in the ATP Race To Milan last year. But, after three-and-a-half months this season, he’s in second place, behind countryman Frances Tiafoe.

“I feel like I’m having very strong results again but I’m playing within myself,” Fritz said. “I’m playing tennis that I know I can go out and play every single time.”

View The ATP Race To Milan

Bob Bryan and Mike Bryan will turn 40 on 29 April. But the six-time Houston champions are showing no signs of slowing down.

The Americans advanced to the semi-finals of the Fayez Sarofim & Co. U.S. Men’s Clay Court Championship on Thursday, beating another team of brothers in Ken Skupski and Neal Skupski 4-6, 6-3, 10-6.

The Bryans raised their level after dropping the first set. They didn’t face a break point in the second set, and in the Match Tie-break, they won all three second-serve return points. The Bryans will next meet Max Mirnyi/Philipp Oswald, who squeezed past Scott Lipsky/Tennys Sandgren 6-7(4), 7-6(1), 11-9.

It will mark the 55^th time the Bryans have faced Mirnyi, who turned 40 last July. The Bryans are 31-23 against the 6’5” right-hander, who has had 22 doubles partners against the American greats.

In other doubles action, Andre Begemann and Antonio Sancic beat 2017 Roland Garros doubles finalists Santiago Gonzalez/Donald Young 7-6(4), 6-2. Begemann/Sancic will next play 2017 Houston doubles finalists Dustin Brown and Frances Tiafoe, who dismissed Ivo Karlovic and Daniel Nestor 7-6(5), 6-3.

DID YOU KNOW?
Houston will be the 24^th event where the Bryans and Mirnyi will have played.