This year marks the 50th anniversary of TENNIS Magazine's founding in 1965. To commemorate the occasion, we'll look back each Thursday at one of the 50 moments that have defined the last half-century in our sport.

“The serves and returns Alves called out were landing, stunningly unreturned by Carpriati, inside the lines, no discerning eyesight needed...No one could understand what was happening. Serena, in her denim skirt, black sneaker boots, and dark mascara, began wagging her finger and saying, “no, no, no,” as if by negating the moment she could propel us back into a legible world.”

There aren’t many evenings in tennis history that are recorded in volumes of poetry that have been nominated for the National Book Award, but the match that brought us Hawk-Eye is one of them. The lines above come from Citizen: An American Lyric, a 2014 book by the poet Claudia Rankine, and they help us recall one of the most surreal and ultimately transformative episodes in recent Grand Slam history, the 2004 U.S. Open quarterfinal between Serena Williams and Jennifer Capriati.

Or, perhaps we should say, between Serena Williams and chair umpire Mariana Alves. As Rankine writes, Alves stunned Serena, and every tennis fan watching on TV, with a series of bizarre calls in Capriati’s favor. They were capped by an all-time awful overrule at the beginning of the third set: A Serena backhand that landed inside the sideline was called in by the line judge; yet Alves, sitting on the other side of the court, “corrected” the judge and called it out. Serena waved her hand in protest, to no avail.


There had been bad calls and inexplicable overrules in the past, of course, but this time there was clear evidence, at least for TV viewers, of the mistakes. Networks had recently begun using a computerized replay system—known as Shot Spot on ESPN—that could clearly show, within a few millimeters, exactly where a ball had landed. The tours, however, had yet to employ the system to make calls on the court, so while everyone in the world other than Alves knew that Serena’s shot had been good, Serena herself was left with no option but to play on. She would eventually lose to Capriati, and receive an apology from U.S. Open officials the following day. Alves, meanwhile, was barred from working any more matches at the Open that year.

While it came too late for Serena, her experience with Alves would give players a way to fight back against bad calls. That week, tournament and tour administrators began to talk about making instant replay a part of the sport, rather than just its telecasts. After a testing period in 2005, Hawk-Eye made its professional debut at the Nasdaq-100 Open in Miami the following spring. Players were allowed a limited number of challenges to calls they deemed questionable; despite fears that this would delay play, the system went off with hardly a hitch. If anything, Hawk-Eye has saved time by largely eliminating the arguments between players and chair umpires that had been a staple of the sport since it was professionalized in the 1970s.

One high-profile, and highly traditionalist, player did resist, however: Roger Federer. When a Hawk-Eye overrule went against him in the 2007 Wimbledon final, he asked, unsuccessfully, to have the system shut off. Yet over the years even Federer has granted Hawk-Eye his grudging acceptance, and in 2014 the system did its best to return the favor. Down match point in the Wimbledon final against Novak Djokovic, Federer hit a serve that was called out, but ruled in by Hawk-Eye. An ace, it propelled Federer to a fourth-set comeback, and nearly propelled him to an eighth Wimbledon title.

Federer’s ups and downs with the system aside, Hawk-Eye has been an unmitigated boon for the sport as a whole. The computer’s ultimate, unchallenged authority has saved the players, and their fans, from thousands of ugly arguments, and helped tennis present a more appealing product to the public. Sadly for Serena Williams, her loss in 2004 has been everyone else’s gain ever since.