NOT many people realize that electronic lines, slated to be used officially for the first time in a Grand Slam tennis tournament at this year's US Open, have been around even longer than John McEnroe, whose steamy courtside invective may well have spurred the development of an infallible line-calling system.
As it happens, neither has been in evidence on court this year. McEnroe took refuge in the television booth, and the United States Tennis Association (USTA) canceled its plans for electronic line-calling on four courts before play started Aug. 30.
The Australian TEL system (Tennis Electronic Lines) encountered some last-minute snags caused by the eyelets on some brands of shoes, metal tips on shoelaces, bracelets, knee braces, keys, watches, and some rackets - none of which happened to have been worn or used by players during a year of stringent testing.
So, with due caution, the USTA temporarily withdrew the TEL equipment despite successful tests at last year's US Open, at the Australian Open in January, and at some hard-court tournaments since then. Clay and grass surfaces present special problems that have not yet been tackled.
``Electronic lines are inevitable,'' says Woodie Sublett-Walker, deputy referee at the US Open. ``As long as you have people that are contesting the calls ... you're going to have someone out there who wants the technology that can say, `This is 100 percent correct.' ''
And the USTA is confident that it will soon have a system working as reliably as any new gadget in its infant stages.
Stan Malless, a former president of the USTA and a line-call pioneer on the USTA Technical Committee, recalls that it was Philippe Chatrier of the French Tennis Federation who first encouraged the USTA to catch up with the technical sophistication of such sports as auto racing, swimming, and fencing.
``Why can you Americans put a man on the moon,'' he challenged, ``but can't develop an electronic line system?''
``Although the logistics of space missions are greater than anything we would encounter,'' says engineer Malless, ``theoretically, the problems are greater in tennis. Out in space, things are predictably in their right place, but a tennis ball comes at you from all angles, speeds, and curvatures, and it never exactly repeats itself. The human eye cannot call a tennis ball at the speeds [up to 125 miles per hour] involved, and with the flattening effect [on impact] that can leave a ball-print six inches long.''
THE USTA has evaluated more than 30 different electronic line-calling systems in the past 20 years, and found the TEL system the best so far. It operates like an upside-down metal detector when tennis balls containing tiny metal fragments pass through its magnetic field.
The chair umpire, who will eventually work alone on court with a computerized handset, activates the service-box lines when a player is ready to serve, and then de-activates those lines and activates (or ``arms'') the outer lines if the serve is successful.
The equipment is sensitive within 12 inches on either side of the line, making the visual calls by the umpire fewer and easier.
When a serve lands in play, a pulse is felt in the handset, and a readout shows by how many millimeters the ball was ``in.'' When a ball lands out of play, a loud ``beep'' is heard on the public-address system, and, again, a precise measurement registers on the handset. (The handset also keeps track of the score.)
Players on the professional circuit are cautious but not opposed to the electronic lines.
Martina Navratilova, a four-time winner of the US Open and now vice president of the Women's Tennis Association, said last week that she welcomed the system's consistency and its accuracy. ``They still have to work the kinks out of it, but, as a line-calling system, it is great.''
Jim Courier, clinging to his world No. 1 ranking after losing to Frenchman Cedric Pioline on Tuesday, is not convinced that electronic lines are inevitable, though he says he thinks its faults are correctable.
But, he adds wryly, ``I think the general consensus among the guys is that we prefer to get angry at lines-people instead of computers.''
Many players are discovering that those much-maligned officials are not so bad after all, and players have made a belated call for less haste in removing the human element.
``But we're not taking the human element out of it!'' Malless adds. ``We still have two humans playing each other to see who is better, and we don't want a third human, having nothing to do with the play, affect that result.''
``It's ridiculous to think that in tennis we often have two people playing against each other in front of 13 officials. With the TEL system operated by a chair umpire alone,'' Malless concludes, ``the USTA could recoup its [substantial] installation costs within two years, and the system would probably last for 20 years.''