Wimbledon chiefs have defended electronic line-calling after Emma Raducanu and Jack Draper questioned the technology during the first week of the tournament.
A fully automated system has replaced human line judges at All England Club this year, ending player challenges of contentious calls.
But Raducanu, Britain's leading women's player, was unhappy after her 7-6 (8/6), 6-4 third-round defeat against top seed Aryna Sabalenka Friday.
The world No 40 said one call in particular, when a shot from Sabalenka was ruled to have clipped the line, was wrong.
"That call was for sure out," said the former US Open champion after the intense battle on Centre Court.
"It's kind of disappointing, the tournament here, that the calls can be so wrong, but for the most part they've been OK.
"I've had a few in my other matches, too, that have been very wrong. Hopefully they can fix that."
The automated technology has become standard across tennis, with all events on the men's Association of Tennis Professionals Tour and many Women’s Tennis Association tournaments using it.
The Australian Open and the US Open are fully automated but the French Open remains an outlier, sticking to human line judges.
Britain's Draper, the men's fourth seed, queried one serve from Marin Cilic during his second-round loss Thursday.
"I don't think it's 100% accurate, in all honesty," he said.
"A couple of the ones today it showed a mark on the court. There's no way the chalk would have showed."
But Wimbledon chiefs said Saturday they were confident in the technology.
"Live electronic line-calling technology is now widely used week in and week out on tour," said a spokesman for the tournament.
"The technology goes through a rigorous certification process and meets the (agreed) standards...so we can provide maximum accuracy in our officiating."
