고등학교 영어Ⅰ (YBM 박준언) 연계 글

In professional tennis, a ball can travel at 50 meters per second. For most of the sport's history, however, every call on whether the ball landed in or out rested on the eyes of line judges and the chair umpire. By the time a camera system reached the professional tours in 2006, players had complained about close calls for decades. Many of them urged that some form of technology be used to settle such disputes.

The system, known as Hawk-Eye, had already appeared in television broadcasts of cricket before tennis officials began to use it. Several cameras around the court follow each shot, and software combines their images to calculate the ball's path. The result is an animated replay that marks the spot where the ball bounced.

In March 2006, Hawk-Eye made its debut on the tours at a tournament in Miami, where players could challenge a line call that they believed was wrong. Each player received two challenges per set, plus one more in a tiebreak. The replay appeared on large screens for the players, the umpire, and the spectators all at once, and a challenge was lost only when the replay confirmed the original call. Later that year, the US Open became the first Grand Slam tournament to use the system.

The replays also revealed how accurate the human officials had been. At Wimbledon, which first used the system in 2007, most challenges went against the players who made them. A study of more than 1,400 challenges at men's tournaments concluded that line judges located a ball's bounce more reliably than players did. In 2008, the governing bodies of tennis set one rule for all events using the system: three unsuccessful challenges per set, plus one more in a tiebreak.

Yet the machine is not flawless. In the men's final at Wimbledon in 2007, it ruled that a shot had clipped the baseline, although the ball had looked well out to the umpire and the player across the net. In 2008, when its maker put its average error at a few millimeters, the social scientists Harry Collins and Robert Evans argued that a single sharp mark hides such uncertainty. They recommended that each replay display the size of its possible error, much as scientists report a margin of error. They also proposed that such images carry a "health warning" so that viewers would not mistake an estimate for a precise record.

Hawk-Eye did not end arguments about line calls; it moved them from what people saw to what a machine measured. The harder question now is how much trust a measurement deserves.