MELBOURNE, Jan 25 (Reuters) - The Hawk-Eye line-call system was called into question at the Australian Open on Sunday when it failed to register a shot on centre court.
The ball tracking system was unable to pick up a shot in the fourth set of the Roger Federer v Tomas Berdych match, probably due to a heavy shadow over the line in question, leaving the Czech player furious.
"What to say? I mean, if they bring some new system and it doesn't work, why should it be on the courts?" Berdych fumed after his five-set defeat to the second seed.
Federer, a long-time opponent of the system, said the incident had only confirmed his doubts.
"It's horrible. I don't like it," he said.
"Tomas doesn't like it since today. Finally one guy understood.
"If it's 9-9 in the fifth set, you know, you got to use it and there's a terrible call because the linesperson was sleeping and the umpire was drinking coffee, of course then it's good you have it.
"But...you have four eyes looking at every line.
"The ball Tomas was questioning was out. But still, a system like this is in place (and) it shouldn't happen, right? That could be the crucial moment for Tomas. It wasn't because it was clearly out. Still, it's not so much fun for him, I guess."
Three of the four grand slams use the technology. The French Open is the only major not to use the system as the ball leaves a mark on the clay surface.
The system was first used at a grand slam at the 2006 U.S. Open.
The sport's governing bodies agreed last year that players will be allowed up to four unsuccessful challenges per set at any tournament that uses electronic line calling systems.
The Hawk-Eye technology reconstructs the ball's most likely path by combining its trajectory with images from cameras positioned around the court.
The International Tennis Federation were unable to comment on the latest incident when approached by Reuters.
Editing by Alan Baldwin