Paris - A behind-the-scenes battle at the world's top tennis tournaments pits an upstart newcomer and an established star.
Hawk-Eye, the British firm that innovated ball-tracking technology, has been ruling the sector for more than a decade.
Its famous video simulations of contested line calls at Grand Slam tournaments are known to tennis lovers around the world.
They are produced by computer-linked tracking cameras that calculate a flight path and project the ball's landing point.
But start-up FoxTenn from Spain believes it can do better by eliminating doubt from the line-call business.
Hawk-Eye, which operates a dozen or so cameras placed around the tennis court, officially acknowledges a three-millimetre or so margin of error in its simulations of where the tennis ball would bounce.
For Foxtenn that tiny margin is too wide and it says it can offer real-time technology that eliminates any room for debate.
"What we are offering is the technology of truth and transparency, with the actual impact of the ball on the court," FoxTenn president Javier Simon told AFP.
In fact, FoxTenn's 40 or so cameras around the court, backed up by scanners and lasers, effectively capture the moment of impact of the ball, without need for any simulation.
Simon says the technology has been given a zero-error rating in a study approved by the main tennis federations, the ATP, ITF and the WTA.
Simon says that so far around 30 men's and women's tennis tournaments have adopted the FoxTenn system, or about 20 percent of the professional circuit.
"Our goal is to equip all the tournaments," he said, particularly the top-tier Masters 1000 events and the four Grand Slams.
Within a few months the line-call contracts will be coming to an end at the nine Masters events, and FoxTenn is lobbying hard for a chance to prove its worth.
One tournament which already uses Foxtenn, Marseille Open, found that initial difficulties were overcome after two seasons.
"At the start, I liked the idea of a challenger for Hawk-Eye, which had a bit of a monopoly," said tournament director Jean-Francois Caujolle.
"Foxtenn seemed lighter to install, a bit cheaper and had real-time images, which is good.
"At the start it wasn't fast enough, but they have made progress, and it's very good. Maybe it will make Hawk-Eye renovate."
Players have other things to focus on and are rarely directly concerned by behind-the-scenes technology.
Roger Federer said he has no idea whether he has been exposed to Foxtenn.
"I doubt it. Yeah, I don't even know about it," he told AFP.
"You know the tournaments I've played. I guess there they haven't used it. Hasn't it been Hawk-Eye all the way?"
French world number 19 Gael Monfils says he is used to Hawk-Eye but thinks FoxTenn may hold a potential edge "because you see where the actual ball landed".