 Federer is one of few players to voice doubts about Hawk-Eye |
Roger Federer remains unconvinced by the Hawk-Eye instant replay system used for the first time in Miami last week. The world number one, who beat Ivan Ljubicic to take the title on Sunday, was successful with only one of the five instant-replay challenges he made.
"I still believe you have to give it time and see if it's really reliable," he said. "I'm happy it's in the past right now."
The US Open plans to be the first Grand Slam to use Hawk-Eye later this year.
Miami's Nasdaq-100 Open became the first event on both the men's and women's tours to use the technology.
The new system allowed players two challenges to line calls per set, with the replays transmitted on large court-side screens simultaneously to the players, umpire and spectators.
A total of 161 calls were challenged in Miami, of which 53 were successful.
"We could not be more pleased with how the video review system worked in its first use, but I also feel this first tournament showed a lot about the professionalism and skill of our line judges," said Gayle Bradshaw, the ATP Administrator of Rules & Competition.
"We look forward to evaluating the entire process, and we will work in the coming months to improve the challenge system in order to make the experience even better for players, spectators and the television viewers."
The WTA's Angie Cunningham said: "Our players have really been impressed with the system, and they are finding out just how hard it can be to call a ball travelling at the speeds that our players hit it these days."