Karlovic set a new record for number of aces in a three-set match as he beat Tomas Berdych at the Gerry Weber Open, while Raonic’s own ferocious serve couldn’t prevent the Canadian losing out in his quarter-final match against Gilles Simon at Queen’s Club.
Raonic hit 23 aces to reach 76 in three matches at the Wimbledon warm-up event and was certain in his answer when asked afterwards who he thought had the best serve on the men’s tour.
“I believe myself,” he said. “My serve takes me a long way.
“I think the serve is not only about what necessarily you can do with it, but it’s how you step up.
“If you look at results, numbers besides names, then my serve has carried me a pretty long way.”
Karlovic could overtake his retired Croatian compatriot Goran Ivanisevic to become the all-time ace king at his current rate.
The 36-year-old has 9,499 aces from 508 matches, at an average of 18 per match, and is second on the all-time list.
Ivanisevic still tops that chart, with 10,183 aces from 895 matches at an average of 11 per appearance.
The 24-year-old Raonic is 36th on the aces list, with 4,166 from 273 matches at 15 per match.
However, another big server, South Africa’s Kevin Anderson, who moved into the Queen’s Club semi-finals with 18 aces of his own in a win over Guillermo Garcia-Lopez, believes Karlovic is the best of his big-serving rivals.
“On sheer numbers in the game, I think I’d have to give it to Ivo,” the World No 17 said, ranking Karlovic, John Isner, Raonic and himself as the world’s top four servers.
“I think Ivo’s first serve is really good. On a second serve I think Isner is a bit tougher than Ivo.”