The close line calls that have had tennis fans booing and whistling their displeasure will be a thing of the past at this week's Legg Mason Classic tennis tournament.  The event will begin using a new technology that will allow officials to immediately review the action on court and verify line calls.

Hawk-Eye Cameras

Fans, players and officials will now have a second chance to look at questionable calls, thanks to the new  technology adopted by the U.S. Tennis Association this season.
 
Already in use for years on many televised matches, the USTA will use the system at U.S. Open Series events and other North American tournaments this year. 

It will be the first year for instant replay at the Legg Mason Classic.  Eighth-seeded British tennis player Andy Murray got his first look at Hawk-Eye in his second-round victory over Paraguay's Ramone Delgado on Wednesday.  Murray said that even though the calls did not go his way, he likes the system.

"I think its very good, unfortunately its the first time I used it today and I was 0-for-3," he said. "That's not good statistics, but its good because you can put the call behind you and I think the fans like it, which is the most important thing.  And, you know, you don't have guys breaking rackets over bad calls now, and I just think its good for tennis."

The impetus to use instant replay technology during matches got a big boost in 2004.  At that year's U.S. Open in New York, American Jennifer Capriati benefited from three bad calls in the quarterfinals that all went against her countrywoman, Serena Williams, who ended up losing the match.  After that, the USTA made it a high priority to develop an accurate and reliable technology to insure correct calls.  Gayle David Bradshaw, Vice President of Rules and Competition for the Association of Tennis Professionals, says the technology is not meant to replace the on-court officials.

"What we are looking for, though, is any opportunity, any way to make sure we get the call correct.  And this is a technology that, right now, is not replacing the line umpires.  We look at it as, it is enhancing the officiating, and that is a positive thing for everybody," he said.

Bradshaw explains how the players use the challenge system.

Hawkeye scre

"Each player, or team in doubles, is allowed two challenges per set," he said. "If they are correct in their challenge then it does not count against their total of two.  And then once they reach a tiebreak, each player receives an additional challenge."

The Hawk-Eye system uses 10 cameras around the stadium court, five per side.  When a challenge occurs, the images from all 10 cameras are fed into a central computer, which projects a digital recreation on a jumbo screen.  The players and fans see the replay simultaneously.

All of the cameras track the ball at all times and are combined to create a single three-dimensional image of the ball's trajectory. The margin of error averages plus or minus 3.6 millimeters.