Tennis’ New Eye Shadow

After worldwide testing and numerous philosophical debates within the sport, professional tennis will enter the world of instant replay, beginning this month at the prestigious Nasdaq-100 Open in Key Biscayne, Fla.

And if all goes as expected, center court in South Florida won’t be an isolated lab experiment. Plans are to use the electronic line-calling system, known as Hawk-Eye, at the U.S. Open this year and possibly at the North American hard-court events leading up to New York, known as the U.S. Open Series. Three of those summer tournaments are held in Southern California, the first at UCLA in July.

Several cameras will track the trajectory of the ball and can determine precisely where it lands. The umpire will review the replay from the chair.

An announcement is expected today, the culmination of a collaborative venture among the U.S. Tennis Assn., the International Tennis Federation and the men’s and women’s pro tours.

Arlen Kantarian, chief executive of professional tennis for the USTA, said it could be the “most significant change” in the sport since the introduction of the tiebreaker. The impetus for such a move essentially came to the forefront when Serena Williams was on the wrong end of several questionable calls against Jennifer Capriati, including a particularly egregious overrule in the third set, during their 2004 U.S. Open quarterfinal.

Open officials even apologized to Williams after her loss. A year later, the USTA had hoped to unveil the system but held off after testing revealed shortcomings.

“We took an extra six to eight months, so we could do this in a consistent and uniform manner with the tours,” Kantarian said.

Identifying the most accurate and reliable technology was one hurdle. Perhaps the most fervent debate focused on challenges of line calls. Players will be allowed two challenges per set and another should the set reach a tiebreaker. A successful challenge -- in which the system shows the initial line call was incorrect -- would not count against a player’s two challenges.

The WTA, for instance, initially wanted unlimited challenges. Larry Scott, chief executive of the women’s tour, called the current plan a compromise.

“A lot of discussion about that back and forth,” he said in an interview with The Times. “What we start with here may not be what we end up with years from now. The NFL evolved and sort of changed their system along the way.”

Etienne de Villiers, executive chairman and president of the ATP, said, “Unlimited challenges would have been the obvious way to go. But the difficult thing is it’s very hard to reverse that position once you’ve implemented it.”

Scott said there were concerns about unlimited challenges from U.S. broadcasters, who said there might be more fan appeal and interest if the challenges were limited. Players also apparently wanted some protection against potential gamesmanship.

Kantarian also spoke of holding on to the human element.

“We felt that an unlimited system would render the game a bit mechanical, a bit robotic,” he said. “We don’t want to turn the game into a video game.”

Scott said he was “pretty certain” the system would be used for the women’s tour’s season-ending championships in Madrid this year, and the ATP is considering implementing Hawk-Eye for its season finale in Shanghai. Additionally, officials were enthusiastic about the interactive potential with the fans in the stadiums.

“Simultaneously, with the chair umpire receiving the replay, it will be shown on TV and in the stadium,” Kantarian said.

The ATP has even included a requirement that tournaments using electronic line-calling also have a large video board in the stadium, which would put the cost in excess of $100,000 for the replay system and video board. De Villiers acknowledged that may be a difficult proposition for smaller events.

“The fans love to see a decision when it’s made,” he said. “Players look up. It’s a very interesting punctuation.”