“Let, First Service”. That is a call familiar to tennis fans who watch the game either in person or on TV. For the older tennis fans among us, like me, a hunched figure sitting next to the net post, head bent, one or two fingers in contact with the net cord, and an ear stuck to the net cord was a familiar sight in tennis matches. This person, an important official of the game, was called a net judge. So, what is a Let?
In tennis, when a player serves the ball, one of the conditions for it to be a fair serve is that it should not touch the net on its way to the opponent. The rules of tennis also let each player get two attempts at a serve, called the first serve and second serve. So, whether the ball grazed the top of the net on its way to the opponent, has to be judged with accuracy and hence human “Let Detectors” were employed. If a served ball touched the net cord and still landed in the designated area on the other side of the net, the net judge would shout “Let” and the chair umpire, would announce, “First service” or “Second service” depending on whether the Let occurred during the first or second service. If there is a Let on the first serve, the player gets further chances till a fair first serve, without let, is achieved. If it turns out to be a faulty serve in other respects, there will be a second serve. There can be a Let on the second serve too. We often hear the call, “Let, first service” called by the chair umpire and less often the call, “Let. second service” because, players usually serve more cautiously and with lesser speed on second serves, fearing two faulty serves (double fault) and losing the point. This cautious second serve reduces the chance of a Let on a second serve.
The job of net judge was not without risks. Balls travelling at really high speeds, either during the serve or during the rally for the point, could hit them, often in the head. A Google® image search for “net judge” gives you many pictures of these judges and also some videos in which these officials have been hit by tennis balls! Replacing the job of a net judge with an electronic device would, hence, be preferable!
A device that sensed the ball touching the net cord and alerted the chair umpire and others through a sound was introduced in tournaments. Apparently, the device consisted of a piezoelectric pick-up for an electric guitar positioned on the net cord and connected to a sound producing device. A patent was applied for, based on this invention, and was granted too. The patent was US5585778A (https://tinyurl.com/37av9j47) based on a German priority application DE9311170U1 (https://tinyurl.com/5549nsbd). The invention is credited to two German inventors: Dietmar Braeuer and Dieter Naber.
Even though there are some reports that say such devices were used as far back as 1974, there is no clear evidence of that. However, the “home of Tennis”, Wimbledon, introduced electronic Let detectors only in 1996 as reported here: https://tinyurl.com/yk3evzew .
However, there have been patents, as early as the mid-sixties claiming just such a device. Here is one such with the priority year 1965 - https://tinyurl.com/y3xa72jm. The forward citations of that patent and “similar” patents listed by the Google® patent search reveals tens of patents that are about impact sensing in sports, including those for detecting a Let. As can be imagined, even a relatively simple device such as the Let detector undergoes improvements and innovations. The initial Let detectors indicated a Let with a loud ping. Nowadays, the event is displayed on the chair umpire’s screen and the chair umpire announces it. One can see that, as in other areas of technology, there are continuous innovations in technologies catering to sports too.
