The Impact of the Hawk-Eye System in Tennis

The Impact of the Hawk-Eye System in Tennis


New technological advances have helped enhance our lives in ways never before thought possible.  Advancements in medicine, warfare, education and even sports have become common and are expected as our society continues to grow.  It is also a common occurrence that new advancements in technology become the target of much scrutiny when they first emerge on the public scene.  In the sport of Tennis the Hawk-Eye System has become a greatly scrutinized piece of modern technology.  Since its inception into the sport many questions have arisen, but none are more important than the question: “Has the Hawk-Eye System improved the game of tennis?”  Before this question can be answered we must first learn about the following: The traditional values of Tennis, The Hawk-Eye System and how it works, why is the system needed?, are there problems with the system?, contributions to the sport and player support.

Traditional Values of the Sport

Before we can begin to discuss the Hawk-Eye System and its validity in the sport of Tennis we must first discuss the sport itself and how receptive it is to modernization.  Tennis has long been a gentleman’s game where honor and truthfulness reign supreme.  Although there are many professional circuits with officiating bodies to watch over them there are far more leagues and recreational players that use the honor system when calling shots.  Most high school, collegiate and adult USTA leagues do not use judging officials for matches so the players must do the line calling themselves.

There is a long standing unwritten rule among recreational players in regards to line calling.  The rule is that if player A hits a shot that is very close to being in or out then player B must be certain of their call.  If player B has any doubt in their mind or is openly uncertain of how to rule on the shot then they must concede the point.  In a professional setting however judging officials have long been integral parts of the game.  Players used to accept line calls both good and bad as a part of the game.  In addition to this haggling so to say with the Chair Umpire is also very much a part of the game that has been popularized by players such as John McEnroe.  Tennis is a sport that is notoriously resistant to change; a player still being required to wear only white at Wimbledon is one example, but while the introduction of the Hawk-Eye system challenges these traditional values it also promises to enhance many aspects of the game.

The Hawk-Eye System

The Hawk-Eye System is a complex computer targeting system that is used to track the path of an object (Hawk-Eye Innovations).  Hawk-Eye was originally created for use in Cricket, but quickly gained popularity in sports such as Snooker and Tennis.  Currently the system is being developed for use in sports such as Soccer and Football.  Hawk-Eye was first introduced to Tennis at the 2003 Australian Open where it was only used experimentally and had no impact on match play.  In 2005 the system passed a series of test conducted by the International Tennis Federation.  These test concluded with the Hawk-Eye System correctly analyzing eighty balls that were fired with an automatic ball launcher in Arthur Ashe stadium in New York City.

(Figure 1)

(Sayers, 2011)

            As illustrated in Figure 1; the overall concept of how the Hawk-Eye System works is fairly straight forward.  What happens behind the scenes where the mathematical equations are processed however is rather complex.  A Tennis court using the Hawk-Eye System will have ten high-speed cameras placed all around it.  These cameras capture the movement of a tennis ball from multiple angles and then feed that information to a computer.  This information is then analyzed sent to another computer where the speed and trajectory of the tennis ball are measured.  Once these measurements have been taken the data is processed by additional computers that use complex mathematical equations to pinpoint the landing spot of the tennis ball within three millimeters.

This information has been implemented into the game of Tennis by way of the challenge system in order to fix errors in line-calling and to make calls more consistent.  The current unified rules regarding the challenge system allots players three challenges per set.  Should a set go to a tie break each player receives an additional challenge.  A player may continue to challenge line calls provided they are correct.  Every incorrect challenge results in a loss of one of the initial three challenges until a player is left with no remaining challenges.  The rules of challenging a line call state that players must challenge the ruling on the court in a timely manner.  This includes the stopping of the current point, approaching the net or indicating to the Chair Umpire by way of the universal sign for challenging a call in Tennis which involves extending one arm overhead with the pointer finger raised towards the sky.  This is reminiscent to someone raising their hand as if to say “hold on for one minute.”

Problems with the Hawk-Eye System

Unfortunately nothing is seldom perfect right away and the Hawk-Eye System is no different.  During the early years of its use many problems arose including some errors involving high profile matches.  As stated earlier; the initial system was approved for competitive use in 2005, but the official rules on how to use this technology were not consolidated until March 2008.  This means that during that three year time span individual tournaments could interpret on their own how the system was to be used at their event.  Some tournaments allowed players to challenge only twice per match while others gave players the ability to challenge for an unlimited amount of times during every match.  This inconsistency of the rules helped only to make the system seem more confusing that it really was to the general public and gave more validity to the arguments of critics.

Another problem involves the decision on where the system will be used.  At major tournaments the only courts that have this technology available to use are high profile courts such as Rod Laver arena at the Australian Open or Arthur Ashe stadium at the U.S. Open for example.  The outer courts on the other hand often have to do without the Hawk-Eye System. This opens the debate of whether or not it is fair that only high seeded players are privileged with using the system.  In addition to this the high profile courts are the ones that will be hosting televised matches and due to this are also given the best officiating staff.  This places lower level players who are on the outer courts at a disadvantage because they will experience the same problems that warrant the need for challenging calls, but will not have the technology to use in addition a lower quality officiating staff.

One unexpected problem that has evolved over the last few years is that chair umpires and line judges have become increasingly hesitant when making calls.  Now that players have the ability to challenge the rulings of these officials; more and more of them have stopped making the calls they are supposed to be making.  The more weight a point carries the more likely it has become that an official will leave it to the players to just challenge.  The instance of delayed calls or officials being caught not paying attention to points has also increased dramatically.  It is now becoming normal for officials to respond with “I do not know” when asked if they thought a ball was on the line or out.  They are afraid to do the job they were hired to do because of the embarrassment of being called out by a challenging player.  Chair umpires do not overrule calls as much as they used to either which is one of their primary jobs during a match.  Instead they too leave it up to the players to just challenge instead of making the ruling themselves.

The final problem involving the Hawk-Eye System involves the time limit rule on challenging.  Players are supposed to challenge in a timely manner and stop playing the current point.  This however is seldom the case.  For example if a ball hits the baseline and player A thinks the ball should have been called out then player A must immediately stop playing the point and challenge that shot.  What happens instead is player A will continue to play the point and depending on if their next shot is successful or not they will then challenge the previous line shot they thought may have been out.  This allows for an unfair advantage to be gained over player B because should player A be allowed to challenge that shot and it was indeed “out” then the point may be allowed to be replayed even though player A continued to play and hit their next shot long.  Some players will even go as far as to ask their chair umpire if they should challenge a particular shot or not and unfortunately some chair umpires will oblige them with advice which also should not be done.

Contributions to the Sport

While it may have some flaws that will no doubt be worked out over time; the Hawk-Eye System has contributed greatly to Tennis.  The introduction of the Hawkeye System has added a new level of strategy to the game of Tennis that never before existed.  Since players now only have access to three challenges per set they must be wise on when to use those challenges. Having the power to challenge any call you please is very tempting especially in this sport, but patience is still a quality that will lead to success in Tennis.  In addition to knowing when to use a challenge a player could also burn a challenge to possibly slow their opponent’s momentum and regain composure during the time it takes for the call to be reviewed should they be in a tight spot.

The Hawk-Eye System has also helped to improve fan involvement at major tournaments.  Spectators watching in the arenas or at home simply love the drama and strategies that the challenge system has created.  Every single challenge that is shown up on the giant video screens in the stadiums is met with fans yelling “oooooooh” as the animated ball travels through the air and towards the line.  If you have watched such an event happen then you would have also noticed how the result of the challenge is never immediately revealed either.  Instead the animated ball will strike the digital court on the screen and then there is a delay as the view of the court is rotated suddenly and the result of “IN!” or “OUT!” flashes on the screen adding to the excitement of the fans.  The Hawk-Eye System not only increases the enjoyment of current fans of the sport, but provides a new element of excitement to help bring in future fans.

The Hawk-Eye System has also been beneficial for helping players psychologically and to solve major on court disputes.  To play Tennis you have to be able to forget every point except for the one you are currently playing.  This means if you double fault on your serve or hit a shot out wide then you must forget it and move on or those errors could affect you mentally in a negative way for the remainder of the match.  Getting over bad calls made by judging officials are also something you must overcome quickly to remain competitive in your match if you will be playing with their service available.  The ability to challenge helps players see for sure whether or not that previous shot was in or out and then move on for the remainder of the match. This is one of the reasons why many players support the use of the Hawk-Eye System.  Current Tennis professional James Blake had the following to say on the matter:

“I don’t need to go to bed now wondering if that serve really was in or out. I looked up. It’s in. There’s no need to worry about that tonight.” (Hawk-Eye Innovations).

The ability to challenge helps reduce the on court stress felt by players as well as help to solve major on court disputes.  There have been many instances where this type of technology could have helped solve a line call dispute and the most prominent one that comes to mind involves none other than John McEnroe.  On January 21st, 1990 John McEnroe was playing against Mikael Pernfor in the fourth round of the Australian Open.  During the match McEnroe became unhappy with a call made by one of the line judges, but his appeal was not satisfied by the chair umpire.  On the changeover after the game; a still upset McEnroe stood in front of the offending line judge and glared at him while bouncing a ball on his racquet close to the judge’s face.  McEnroe was given a code violation for his intimidating behavior.  Later in the match McEnroe was given a second code violation for smashing his racquet and then the match was defaulted in Pernfor’s favor after McEnroe became vulgar with the chair umpire.

This whole incident could have been avoided if technology like Hawk-Eye had been present at the time.  The line call that started everything could have been challenged and given McEnroe some peace of mind for the remainder of the match.  This whole ordeal was very unfortunately because McEnroe was not the only one negatively affected.  The default of the match tarnished the whole tournament because McEnroe was projected to win the whole thing because of his level of play.  Also the fans came there to see John McEnroe play and they were denied that after he was disqualified.  This event no doubt cost fans money and possibly the tournament money if they had to refunds to fans later on.  The Hawk-Eye System inadvertently helps to stop incidents like this from happening again.

Serena Williams vs. Jennifer Capriati

The need for technology such as the Hawk-Eye System came about at the 2004 U.S. Open in New York City.  The call for action came about after a women’s quarterfinal match between Serena Williams and Jennifer Capriati.  Serena Williams easily took the first set winning 6-2. After this set however things took a turn for the worst.  As the match went on multiple line calls and overrule errors were made against Serena Williams.  Williams lost the second set 6-4 and the third set as well as the match 6-4 to Jennifer Capriati.  During the opening game of the third set Chair Umpire Marina Alves overruled the first point which was later found to be an incorrect call.

After the match video footage showed that there were numerous officiating errors that resulted in Serena Williams losing the match.  As a result of this Marina Alves was dismissed from her post and any future dealings with the U.S. Open.  This whole ordeal threw Tennis and line-calling into the media spotlight.  A major outcry from fans and players alike for some something to be done lead to more serious thought being put into implementing the Hawk-Eye System which was previously experimented with at the 2003 Australian Open.  Next would come the aforementioned stringent testing of the system from the International Tennis Federation and its eventual implementation in October of 2005.

Positive Player Reactions

The ever strained relationship between players and judging officials is nothing new to those who follow this sport.  This makes it no surprise that the vast majority of players would be in favor of such technology.  Many past and present players view the implementation of the Hawk-Eye System into their sport as something that is positive and exciting. The opinion of the players is by far the most important as they are the ones who are most affected by its use.  When asked about his thoughts on the Hawk-Eye System Tennis legend Andre Agassi had this to say:

“In my 20 years in professional tennis, this is one of the most exciting things to happen for players, fans and television viewers. This new technology will add a whole new dimension to the game“ (Hawk-Eye Innovations).


            Most veteran players have been quoted as saying that they wished they had such technology to use when they played the game.  Many younger players such as Andy Roddick have been quoted making comments about how they relish the opportunity to “embarrass” judging officials as well.  The ever opinionated John McEnroe had this to say about it:

“If anyone’s been listening to my commentary the past year then they know I’m in favor of using replay. I think it will make tennis more interesting“ (Inside Tennis, 2008).


This kind of support from the players really helps to promote and validate the use of the Hawk-Eye System.

Negative Player Reactions

Even though the vast majority of Tennis players are in favor of using the Hawkeye System there are still bound to be some who are against it.  In this case the two leading voices against using this technology also happen to be the two best players in the world.  Both Roger Federer and Raphael Nadal have both made it very clear they do not appreciate the addition of the Hawk-Eye System in their sport.  The opinions of these two players carry with them much weight due to their positions as the number one and two ranked players in the world as well as their winning records.  Roger Federer has been quoted as saying the following:

“They tend to now just let us do the work, you know, the tough stuff. They let us get embarrassed basically“ (McIntyre, 2007).

It is clear that Roger Federer does not see things like Andy Roddick does.  His main point stems from the problem previously discussed about how judging officials are now hesitant about making calls in matches.  He also does not believe that this technology is accurate, is extremely reluctant in using it and frequently request that it be turned off for his matches.

Raphael Nadal has had quite a different experience with the Hawk-Eye System which has been the source of his disdain for the technology.  At the 2007 Dubai Championships Raphael Nadal was playing Mikhail Youzhny when a controversial moment involving the Hawkeye System emerged.  Nadal became enraged when Youzhny hit a shot that Nadal believed to be out, but Hawk-Eye ruled that the shot was in.  “The makers of Hawkeye explained that Nadal could not see the full stretched impact of the ball on the courts surface, whereas Hawk-Eye could” (O’Callaghan, 2011).

The Verdict

Has the Hawk-Eye System improved the game of tennis? The answer to this question is yes.  The Hawk-Eye System has done much to improve the game of Tennis by adding new levels of player strategy, increasing fan involving and by helping to settle major on court disputes.  Although there are some problems with the system, they will in time be sorted out and the use of Hawk-Eye will become smoother.  The opinions and arguments of those against using the system are a minority in the matter and as the technology adapts these arguments become less valid.  While there is much tradition in the sport of Tennis; Hawkeye poses no threat to breaking those core values.


Hawk-Eye Innovations, . (n.d.). Retrieved from

Inside Tennis, Initials. (2008, January 31). Hawk-eye technology: big brother is watching. Retrieved from

McIntyre, M. (2007, January 17). Federer slams hawk-eye, asks for changes in heat rule. Federer attacks hawk-eye, Retrieved from

O’Callaghan, J. (2011, January 29). Controversial hawk-eye moments. Top Five Facts, (16), Retrieved from

Sayers, C. (Photographer). (2011). Hawk-eye. [Web]. Retrieved from


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