Ivo Karlovic was pretty satisfied with his performance at Wimbledon. The giant Croatian had one of his best Grand Slam showings, reaching the fourth round and going four tough sets against Andy Murray.

He had just one complaint. "It was only 29 aces," said Karlovic, drawing laughter from journalists.

It's an amount most players would be thrilled with, especially against one of the world's best returners. But Karlovic has good reason for keeping track of how many aces he hits these days. During his upset win over Milos Raonic at the Rogers Cup in Montreal on Tuesday night, Karlovic hit his 10,000th career ace. His finished the 7-6 (1), 7-6 (1) victory with four more, and his total of 10,004 is second only to Goran Ivanisevic, who struck 10,183 aces since tour record-keeping began in 1990.

Karlovic knows that he could soon become the King of Aces.

"Yes, I would really, really like to be able to do it, break the record," he told TENNIS.com at Wimbledon. "It will go in the books so of course I would like to do it. He isn't a lot in front of me, and I believe I can do it this season."

Karlovic knows only approximately how many aces Ivanisevic hit, but is being kept informed of his own total by ATP officials, who tell him his updated stats after almost every one of his matches. There's even a target date. "The US Open, maybe—no, I don't know," he laughs. "But this year."

The 36-year-old was 221 aces behind Ivanisevic going into the Rogers Cup, with three tournaments to play through Flushing Meadows. That's almost the same amount of aces he hit in his previous three tournaments, the fast-court events at Wimbledon (grass), Newport (grass) and Bogota (hard). But even if Karlovic fails to set the record on North American hard courts, the slicker surfaces that follow—including those at indoor events—should give him plenty of opportunity if he plays a full season.

Karlovic already leads the way in terms of points won when he gets his first serve in, winning 83 percent of career first-serve points, compared to 82 percent for Ivanisevic and Milos Raonic (as of this week).

Challenging for such records shows how far Karlovic has come since announcing his arrival at Wimbledon 12 years ago, when he stunned defending champion Lleyton Hewitt in the first round. Then a shy unknown with a stutter, Karlovic has since won six singles titles and cracked the Top 15 (in 2008), and has developed a distinctive, more assured personality who regularly shows his humor and enjoys a little attention. His Twitter account, @ivokarlovic, is a hilarious must-follow.


But it goes beyond that. Very few players can say their best shot is an example of the greatest the game has ever seen, but Karlovic can with his serve. It's particularly special given the generation that he has grown up watching and playing against. “It's unbelievable," Karlovic said. "Because there was a lot of great servers, Ivanisevic, [Andy] Roddick, [Boris] Becker, [Pete] Sampras, and also now [Milos] Raonic, [John] Isner. And to be the best, of course, it means a lot."

He has reached such heights almost literally. Officially 6'10" when he first came on tour, Karlovic is the tallest man to play at the top professional levels of the game, giving him both unprecedented angles as well as huge power when serving the ball. "Obviously height helps a lot, but I like to think it's not only because of that,” Karlovic said. “So angles that I can do, speed, my strength, technique, and...all of that," he added, breaking off with a self-conscious look before adding, ''Not to [be] cocky or anything."

In addition to the all of the attributes Karlovic describes, his serve was also the product of history, circumstance, and unrelenting effort. "I think it was, because I was really hitting it a lot," he said. When I was younger I was hitting a lot of serves, because it was war, so I don't have a lot of opportunity to hit like normal. In the evening, when courts would be empty, I would serve, hours and hours, even if it was dark. I did this and that is why it so good now, because I really had a lot of hours on it."

There is occasional talk about who owns the best delivery on tour—Isner is sometimes said to have the best first-second combo, while Raonic has staked a claim based on how he backs up his own first serve. For Karlovic, such discussions are unnecessary. "Talk, why?” he laughs. “Stats—it's obvious, I think. Because I hit the most aces, if you look, every match. And also service games won, first serve, points won.”


The statistics are even more revealing in terms of aces per match. The 10,183 aces Ivanisevic hit came in 895 ATP and Grand Slam matches while Karlovic, who spent a good portion of his career on the Challenger circuit, has played only 527 such matches. Karlovic’s average of 19 aces per match is almost double that of Ivansevic, as well as other legendary servers like Roddick, Becker and Sampras.

As he aims to set the ace mark, Karlovic is also conscious that he is chasing a compatriot in fellow Croatian Ivanisevic, who often makes mention of it.

"Almost every week. And he said that if anybody had to take him, he is glad that it would be me," said Karlovic. "When I was little I was always watching his matches and he was my idol. I remember when I first met him I was starstruck, but yeah, to be able to do this, it's unbelievable."

Ivansevic concurred, telling TENNIS.com, "Yeah, if someone has to break it, it might as well be him—he’s from my country, he's a nice guy, he's playing amazing as his age, 36, probably one of the best servers.


Karlovic passes 10,000 aces in win over Raonic, but seeks another milestone

Karlovic passes 10,000 aces in win over Raonic, but seeks another milestone

"With his height, he has angles you don't have," he added. "But he has such a smooth swing, though to read.”

The former Wimbledon champion laughs off suggestions of a comeback to protect his record. "Two Croatians, one and two, it's not bad," he said. "For aces, I would never come back."

According to Karlovic, Ivanisevic is the reason Croats—including Ivan Ljubicic and Marin Cilic—have excelled at serving. His innovative motion was copied by his compatriots. "I think it begins with Ivanisevic, everybody was always watching him and everybody try to do like him, that motion and everything,” said Karlovic.

“And it's also the genes, a lot of us is tall.”

Despite his game-changing shot, Karlovic insists that what he wants to do most of all is win matches, not hit unreturnables. Karlovic is one of three players who have beaten world No. 1 Novak Djokovic this season, doing so in Doha. "It's not like every match I chase aces. I try to win, but if there is a lot of aces, even better," he said.

But while he is going for the record, those priorities might be reversed.