Benefits of the electronic eye

NRL's use of the Video Referee provides assurance as to whether a team has scored. Photo / Getty Images

Many sports have embraced technology to aid in reducing controversial calls from referees and umpires.

TENNIS

* Why and when it came in?
The Hawk-Eye line-calling system might have made its debut at a regular ATP tournament in Miami, but it was served to the masses for the first time at the 2006 US Open.

Since time immemorial players had been carping about the eyesight of the line judges.

Some took their grievances to the extreme, with Romanian bad boy Ilie Nastase throwing a shoe, a towel and several colourful insults over the course of his career.

Obnoxious Americans Jimmy Connors and John McEnroe were not always enamoured of their inferiors ruling on the lines.

Hawk-Eye uses six or more computer-linked television cameras around the court. The computer reads in the video in real time, and tracks the path of the ball on each camera. These six separate views are then combined together to produce a 3-D representation of the path of the ball.

* What can it rule on?

Line calls. It is most commonly used on the service line with serves regularly topping 220km/h, that would test the eye-sight of the most ardent carrot eaters.

Players get two incorrect challenges per set and at most tournaments the expensive technology is available only on the show courts.

* What has it done for the sport?

It has taken most of the temper tantrums out of the game and it has undoubtedly improved the accuracy of calls in the major tournaments where it is in play (you only have to make a trip to Auckland's Stanley St for two weeks in the New Year to see plenty of reasons why Hawk-Eye is a good thing).

Because the information is available instantly, there is no delay and at the US Open in particular, the crowd find the anticipation that builds during slow-mo images on the big screen almost as entertaining as the match.

It is not universally popular however. Roger Federer hates the system and would like to see it scrapped. In the early days he pointedly refused to use his challenges, even when there seemed to be evidence for him to do so. He has recently softened his stance.

LEAGUE AND RUGBY

* Why and when it came in?

League had been in agreement for years that too many games were being decided by appalling decisions in the in-goal. The players, coaches and fans all wanted television replays, but the administrators cried poor. Then Rupert Murdoch turned up with Super League in 1996 and the game was awash with money.

Super League kind of went away, but the telly refs stayed.

Rugby, as befitting a sport where the bulk of its administrators still pine for the days of shamateurism, took longer to cotton on. Australia started using telly to rule on tries in 1999 but, because they couldn't be seen to be copying league, they called theirs the "television match official" rather than the "video ref".

* What can they rule on?

Essentially they rule on tries, though league has widened its brief to analyse the play leading up to the try. In rugby it is basically all about the grounding, though with there often being a heap of bodies around the ball, they have far more inconclusive evidence to deal with than their league brethren.

* What has it done for the sport?

There is still the odd controversy around the awarding of tries, but far less than in the dark ages. The controversy usually involves the interpretation of the grounding laws.

Perhaps the most far-reaching effect video technology has had on the sport is it has eradicated most of the filth. You might not be caught by the ref, but chances are you'll be caught on camera and a long time on the sidelines could ensue (unless you're a superstar and get let off on a technicality).

NFL

* Why and when it came in?

The National Football League first adopted a limited Instant Replay system in 1986, though the present system began in 1999, bringing the opportunity to challenge on-field calls of plays.

It involves the hilarious sight of the referee leaving the field and putting his head under a curtain where he watches the telly for 60 seconds.

* What can they rule on?

Too many rules to mention them all, suffice to say each coach is allowed two opportunities per game to make a coach's challenge. Before the 2004 season, the instant replay rule was changed to allow a third challenge if both of the original two challenges were successful.

The coaches throw a red flag on to the field, indicating the challenge to the referees. The referee has 60 seconds to watch the footage and decide if the original call was correct. The referee must see "incontrovertible visual evidence" for a call to be overturned. If the challenge fails, the original ruling stands and the challenging team loses a timeout. If the challenge overrules the previous call, the call is reversed with no loss of a timeout.

* What has it done for the sport?

Ask not what it has done for the sport, but what it might do for the country. A recent report suggested the same video technology the NFL uses for instant replay during football games could soon help monitor battlefields in Afghanistan.

In the NFL it is such a way of the game, few can imagine life without it. Most people would prefer to see its brief enlarged rather than reduced even if the rest of world thinks there's far too many stoppages of play in American football anyway.

Instant replay has recently been adopted by baseball to rule on home runs.

CRICKET

* Why and when it came in?

It first appeared in 1992 to rule on close run outs and stumpings. Because of the different angles the balls were being returned from and the fact umpires were having to watch the stumps being broken and bats being grounded, the number of poor run out decisions was staggering.

Since that day, cameras have been brought in to rule on catches and no-balls, while Hawk-Eye technology is employed for lbws. Audio technology is used for contentious caught behinds.

* What can they rule on?

Pretty much anything, though each side has only two incorrect referrals per innings up their sleeve.

* What has it done for the sport?

The introduction of technology has been problematic in cricket, due 80 per cent to the rule makers, 10 per cent to the technology and 10 per cent to cricketers who are brought up to believe cheating is OK.

Using the third umpire for run outs and stumpings has been fine, though often the frame-by-frame is too slow to catch the exact point where the stumps are broken.

In adjudicating catches it has been hopeless. Catching the ball above the grass-tops is very much a feel thing. The camera can never conclusively judge whether a fielder has slipped his fingers under the ball and too often the batsman gets the benefit of the doubt. If fielders could be relied upon to be honest and batsman relied upon to rely upon the fielder's honesty, this schemozzle would be solved, but every series seems to have a flashpoint around the claiming of a catch that wasn't.

As for the introduction of leg before and caught behind referrals, the International Cricket Council has handicapped the technology by stating the television official must have conclusive evidence the on-field umpire was wrong. That's too tough a criteria to meet and has resulted in farcical decisions being upheld. A simple rule of common sense would be better.

Also, it should be the umpires, not the players, who call for the third umpire.

Still, it's better than it was when diplomatic relations were threatened and vague accusations of racism were aired whenever there was an umpiring controversy.