Diego Maradona's 'Hand of God'. Geoff Hurst's 'ghost goal' in the final of World Cup 1966. Frank Lampard being deprived of a rightful goal in World Cup 2010. These and many other instances of oversight on the part of the referees have had significant consequences, often completely turning the course of matches, that too at crucial stages of the tournament. FIFA realised that it simply could not afford such howlers at the grandest stage of football. What could they have done to stamp out these human errors? The answer lay in taking recourse to technology. The answer was Video Assistant Referee (VAR).     

VAR debuted in England in November 2017 when the hosts faced Germany in a friendly. It was used extensively in the Confederations Cup, Bundesliga and Serie A. It was used in a World Cup for the first time at the ongoing edition in Russia.  

What is VAR?

It is probably the first time in the history of football when technology is being used to make or change decisions. A team of four people review decisions made by the on-field referee by watching video replays of an incident.

Currently, in Russia, a centralised operation room in Moscow reviews the decisions, irrespective of where the match is being played. One lead video official and three assistants have access to all the cameras of a particular stadium. They also have two dedicated cameras to monitor possible offsides. Eight of the cameras provide 'super slow-motion' and four of them offer 'ultra slow-motion' pictures.

When is VAR used?

There are four cases when the VAR can be called upon.

1. Goals and incidents leading to a goal

2. Offside and penalties

3. Direct red cards: Given that a direct red card results in a one-match suspension, VAR will review such decisions in order to remove errors. However, this will not be applicable to second yellow card ejections.

4. Mistaken identity: If a referee sends a wrong player off the field, the mistake can be rectified through the use of VAR. 

How can VAR be initiated?

The on-field referee can ask for a review. If the VAR team spots something that needs to be reviewed, they can ask the referee to refer the decision to them. The VARs will send the information to the head video official, 

The Head official can review the decision again or accept the already made decision and come to a conclusion.

The VAR will communicate the final decision to the referee.

The referee can then change or stick to their decision based on what the VAR reports.

Instances when VAR could've changed the game

VAR system could right several wrongs done over the years in World Cups. Here are some of the examples:

Geoff Hurst's 'did he did he not' goal in 1966 World Cup has kept football fans scratching their heads for years. In 1996 football scientists at the University of Oxford and Imperial College London claimed that England’s third goal in the 1966 World Cup final did not cross the line after reviewing footages from the game. This is similar to what VAR system can do in a few minutes today.

Another incident is the infamous goal by Argentina's Carlos Tevez in the round of 16 against Mexico back in 2010. Lionel Messi kicked the ball towards the goal away from the Mexican defenders. But what the linesman missed was that Carlos Tevez was ahead of the play and in an offside position when he pushed the ball in. Mexico cried foul. But the decision wasn't overturned.

And the incident that sparked the debate of a need for VAR was Frank Lampard's disallowed goal in 2010 World Cup in the Round of 16 against Germany. Germany was already ahead with two goals to their name against England's one goal. Frank Lampard shot the ball towards the goal. The ball hit the upper goalpost and had bounced over the line. The referee gave the decision to Germany. England lost the match 4-1. However, the goal was highly debated and it was later revealed that it was indeed a goal.

How has VAR fared in FIFA World Cup 2018 Russia?

The system has already courted controversy this FIFA World Cup. VAR failed to award Harry Kane two penalties in England’s opening World Cup win over Tunisia.

Steven Zuber’s equaliser in Switzerland’s draw with Brazil was also allowed to stand despite the goalscorer pushing Miranda.

Another penalty appeal, by Argentina's Cristian Pavon, was dismissed after a challenge from Iceland's Birkir Saevarsson.

However, VAR has made several correct decisions in the World Cup so far.

Already 10 penalties have been awarded in 17 matches. 

Diego Costa netted a goal in the match between Portugal and Spain. But not before sending Portugal defender Pepe crashing to the ground. VAR was brought into action. After several replays, the goal was allowed to stand.

Paul Pogba made a neat pass towards Antoine Griezmann in the France vs Australia match. Griezmann was tackled to the ground by Australia's Josh Risdon. The umpire called for the play to go on.

These decisions have divided fans and players alike over the system.

However, Indian captain Sunil Chhetri is of the opinion that using VAR gives an artificial feel to the game. 'If a country is in the receiving end of a bad judgement, they will always say VAR is important. It makes it clear and fair," said Chhetri.

"I am a little orthodox. I do not like too much technology in the game. It is the best game in the world because you let it flow," Chhetri further said.

The Indian captain also spoke of the human aspect of football and why not using VAR will only add to the excitement of the game.

"There are some mistakes because referees are human. In the past we have allowed these mistakes because they are human. Small things can make a big difference. If I am at the receiving end I will say where is VAR? Why is it not there? Apart from this I think we should stop here. I think we should allow this game to just flow. There will be mistakes by referee which is fine. I love the way the game is right now. Stoppages is not very great for a sport. In football we don't have many stoppages," said Chhetri.

Although the VAR system has its fair share of supporters and detractors, it is here to stay.