Fault analysis through the eyes of an Umpire

by Satendra Bhola , Transend Networks Pty Ltd, Australia

Power system fault analysis is Satendra Bhola’s passion and that is what keeps him going all year round at Transend Networks, a utility which owns and operates electricity transmission network in Tasmania, Australia.

However, every year during the last two weeks in January, Satendra focuses on a different type of fault … a line fault on the tennis courts whilst umpiring matches at the Australian Open Tennis Grand Slam Tournament in Melbourne Park, Australia.

How it all began: I started playing tennis while working in Bahrain for the Ministry of Electricity and Water as our daily woking hours were from 7:00 AM till 2:00 PM. This gave me ample time to get involved with the game of Tennis. After migrating to Australia in 2001, I continued playing tennis at local tournaments, but after undergoing surgery in 2009 to fix nagging back pain, I was advised to substantially reduce playing tennis. This constrain turned out to be the catalyst for me to get involved with the officiating side of tennis as opposed to playing. So I became a tennis umpire, and I love it!
To become a tennis umpire is not that difficult. Most countries have some sort of body responsible for developing tennis officials. In Australia, Tennis Australia runs officiating courses from time to time which needs to be followed by on court practice sessions. This one generally prepares you to officiate at matches as a line umpire at local tournaments.

In order to understand the role of the tennis umpire we need to know a little bit about the rules of tennis. The court is divided across the middle by a net suspended by a metal cable which shall pass over or be attached to two net posts at a height of 3 ½ feet (1.07 m). The height of the net shall be 3 feet (0.914 m) at the center. (See Figure 3.) All court measurements are made to the outside of the lines. The players/teams shall stand on opposite sides of the net. The server is the player who puts the ball into play for the first point. The receiver is the player who is ready to return the ball served by the server.

Unless a fault or a let (when the ball hits the top of the net) is called, the ball is in play from the moment the server hits the ball, and remains in play until the point is decided. If a ball touches a line, it is regarded as touching the court line.

  • Immediately before starting the service motion, the server shall stand at rest with both feet behind (i.e. further from the net than) the baseline and within the imaginary extensions of the center mark and the sideline
  • When serving in a standard game, the server shall stand behind alternate halves of the court, starting from the right half of the court
  • In a tie-break game, the service shall be served from behind alternate halves of the court, with the first served from the right half of the court
  • The service shall pass over the net and hit the service court diagonally opposite, before the receiver returns it. The server cannot touch the baseline or the court with either foot, and cannot touch the area outside the imaginary extension of the sideline with either foot; or touch the imaginary extension of the center mark with either foot. If the server breaks this rule, it is a “Foot Fault.”

The role of the line or chair umpire is to determine when the ball is in play or there is a fault. Calling foot fault is a tricky one as you have to watch the position of the foot at the same instant when the racket makes contact with the ball. Most of the players keep the tip of their shoes just few millimeters away from the line and hence one has to be very careful in calling foot faults. Jo Wilfried Tsonga was foot faulted at the Australian Open 2013 for crossing the center line mark. This call can only be made by an umpire positioned at the center service line at the opposite side.

Electronic Review System: We are humans and at times do make mistakes, especially when the serve is coming at around 240 kmph. The players can challenge the umpire’s call. In the past the judgment was made by inspecting the mark left by the ball on the court. Just as the whole ball game has changed in our Protection and Control world with advent of numerical relays, similar changes have happened in the world of tennis umpiring with the advent of Hawk Eye system.

Line calls in major tennis tournaments are now computed and projected by the highly advanced Hawk-Eye tracking system which is used as part of the Electronic Review System.
It uses high frame-rate cameras to capture the exact 3D position of the center of a tennis ball, recording the action at a rate of 60 frames per second (fps). The computers capture these time-lapsed images taken by the cameras positioned at different directions across the court to map the trajectory of the ball, calculating data at the rate of one billion equations per rally. Virtual reality software turns the calculations into a graphics for viewers to see and understand.

It was first used at the Australian Open at Rod Laver Arena in January 2007 and now is an integral part of ATP, WTA and ITF tournaments across the globe. The professional game is won or lost on the smallest of margins so it makes sense to use the technology to assist us in making correct line calls. It uses 10 or more high speed cameras strategically positioned around the main tennis arena. The system works in a four-stage process:

  • Firstly 2D vision processing is used to identify the center of the ball within each frame of multiple cameras
  • Secondly, the Hawk-Eye system triangulates the information from each calibrated camera to provide the 3D position of the ball
  • Thirdly, the triangulation process is repeated for each frame of the replay, generating a 3D trajectory for the travelling ball

Finally, computers determine the amount of compression the ball will undergo as it touches the ground, giving a bounce mark wider than the ball with an accuracy of 2-3mm
This is used to deduce the landing of the ball, and to present a visual representation to the officials and public. My personal record with Hawk Eye in this year's Aussie Open was 80% as I was challenged five times and got it right four times.

Being a tennis umpire: Every major tournament has a Chief of Umpires who allocates the positions depending on the grading of an umpire on a particular line like: base line, service line and long lines. I don’t really have a preference, as all lines are equally important. I have also been a chair umpire at some local club tournaments in Hobart and in Bahrain where we used to organize the Bahrain Open Tennis Tournament.

During the Australian Open sometimes the temperature gets very high to around 40 deg C. Interestingly enough once again it's all about Protection like wearing a wide brim hat to protect from the hot sun, goggles for eye protection and neck coolers to cool the body. We have an hour on and hour off roster which is very useful in maintaining high level of concentration and getting respite from heat on those hot days.

The Australian Open Extreme Heat Policy (EHP) is applied at the Referee's discretion. At the Referee's discretion, when the Wet Bulb Globe Temperature only (WBGT) is equal to or above the pre-determined threshold, the Referee may suspend the commencement of any further matches on outside courts. Any matches currently in progress will continue until the end of the current set.

At the completion of the set, play will be suspended. Where play in any match commences outdoors (or with a roof open) at the Referee's Discretion, the match will continue until the completion of the set. At the end of the set, a decision may be made by the Referee to close the roof for the remainder of the match and the following matches, when the EHP is still in effect. The roof will only be closed because of extreme heat if a decision has been made by the Referee to suspend the completion or commencement of matches on the outdoor courts.

Being a tennis umpire puts me in a box seat to watch and call the shots. During these two exciting weeks in Melbourne’s Olympic park, I get to see top tennis players around the world in action trying to compete in the first slam (one of the four most important tennis tournaments) of the year. It takes a great deal of concentration on our part to keep eye on the ball travelling at high speeds and being able to make the right call at spur of moment. During my four year stint with tennis umpiring at various ITF, ATP and WTA tournaments, I had the privilege of umpiring matches of top seeded players like Andy Murray, Serena Williams, Victoria Azarenka to name a few.

The most unforgettable moment of my umpiring career so far, was watching Ms. Esther Vergeer in action. She is the most dominant women’s wheelchair tennis player.


Satendra Bhola BSc (Engg), MTech, MIET, CEng has over 33 years of experience in design, testing, commissioning and maintenance of power system plants and applied protective relaying schemes. He graduated in Electrical Engineering from Birla Institute of Technology (Ranchi) and has a Masters in Power Apparatus and Systems from IIT (Delhi). He started his career in Mumbai, then joined the Ministry of Electricity and Water in the Kingdom of Bahrain.

Presently Satendra Bhola is a Principal Engineer with Transend Networks in Australia.

Satendra is very active in officiating tennis tournaments as Chair & Line umpire at various WTA, ATP and club tournaments. He is also a practising Justice of Peace in Tasmania, where he lives with his wife Indu.



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