Charles Petzold

Tennis and Technology

January 23, 2008
New York, N.Y.

During the first week of my freshman year at Stevens Institutute of Technology, the various organizations and sports teams attempted to seduce us into joining up. Our class of budding engineering and science students were quite impressed when the fencing coach told us that his sport was the only one "with a completely electronic scoring system."

Over the past few years, several sports have been edging towards more mechanized umpire calls, most notably tennis. A technology called Hawk-Eye — here's the Wikipedia entry and the company's site with their how it works — places multiple high-speed cameras around the court, and does a computer composite of the ball's motion. For tennis, the crucial information is whether the ball hit the ground inside the line, outside the line, or touched the line at all (which counts as in).

The technology was first used by TV broadcasters as a virtual instant replay to double-check the line refs, but has recently been adopted by several major tournaments. Right now, it's being used at the Australian Open in at least two courts. On any match on these courts, each player gets three "challenges" per set if the player feels the line ref called the ball incorrectly. The computer simulation is shown on a JumboTron and the spectators make a crescendo "Whooo" sound as the animated ball strikes the ground. If the line ref was wrong and the player correct, the score is adjusted or the point is replayed, and that challenge doesn't count toward the three-set maximum.

Some players are somewhat opposed to the technology — more philosophically than practically, I suppose — but most players like it, and the spectators get into it, and it tends to lead to fewer "You cannot be serious!" meltdowns.

Tennis has always been susceptible to mistaken calls. This may be one reason why a game must be won by two points, and a set won by two games. It's a built-in buffer for errors. The problem has probably become worse in recent decades as aluminum rackets have greatly increased ball speed. I don't know if the Hawk-Eye technology can actually be applied yet in real time — and sometimes it's not possible at all if one of the cameras is blocked in some way — but it's not hard to imagine a time five or ten years in the future when all line calls in major matches are judged electronically.

Meanwhile, the women's side of the Australian Open is making history this week: Two women from Serbia have reached the semifinals. Twenty-two year old Jelena Janković will go up against Maria Sharápova, and 20 year old Ana Ivanović will meet Daniela Hantuchová (whose appearance in the semifinal is a little bit of miracle in itself). The two women's semifinals will be begin at 1:30 PM Thursday afternoon in Melbourne, but by a strange time-warp effect can actually be viewed in the U.S. Wednesday evening (tonight) starting at 9:30 PM EST on ESPN2

Deidre and I will probably miss a bit of the Janković / Sharápova match — we're in the city right now and we'll be driving back to Roscoe this evening — but I suspect the Ivanović / Hantuchová match will be fun as well.