It was 30 years ago? You cannot be serious!

London: It was 30 years ago this week when John McEnroe uttered what has become the most immortal phrase in tennis, if not all sport, when he screamed "you cannot be serious" at a Wimbledon umpire while disputing a line call.

For players brought up in an era of Hawkeye electronic detection devices, when line-call challenges are enshrined in the rules of the game, it is impossible to understand the furore McEnroe's outburst caused in the civilized world of tennis.

McEnroe already had a reputation and had been labelled "Superbrat" by the British tabloid media for his verbal volleys during his previous Wimbledon appearances.

His moment came in a first-round match against fellow American Tom Gullikson, who was serving at 15-30 and 1-1 in the first set when a McEnroe shot was called out.

Approaching the umpire, he said: "Chalk came up all over the place, you can't be serious man."

Then, his anger rising, he bawled the words that would stay with him for a lifetime and, for all his wonderful play and myriad achievements, earn him a special niche in the sporting annals.

"You cannot be serious," he screamed. "That ball was on the line.

"Chalk flew up, it was clearly in, how can you possibly call that out?" he went on.

"Everybody knows it's in in the whole stadium and you call it out? You guys are the absolute pits of the world, you know that?"

On the receiving end of the tirade was umpire Edward James, who eventually responded by politely announcing: "I'm going to award a point against you Mr McEnroe."

That was not the end of it as the referee was later called amid another rebuke for the headband-sporting, wild-haired American after he smashed his racket into the hallowed turf.

"You are misusing your racquet, Mr. McEnroe," said James.

"You are an incompetent fool, an offence against the world," boomed McEnroe, who was docked another point.

It made little difference in the end as McEnroe went on to win in straight sets to begin a campaign that would end two weeks later with his final victory over Bjorn Borg.

Gullikson was unimpressed, saying at the time: "It has no place. Everyone's afraid of these guys. All it would take is one default to put them in line. If it was the 120th player in the world they would have defaulted him."

The outraged Wimbledon officials were equally annoyed and broke with tradition by not making their new 22-year-old singles champion an honorary member of the All England Club.

McEnroe boycotted the Champions' Dinner in response, missing a chance to dance with women's champion Chris Evert in the process.

"You cannot be serious" moved quickly beyond tennis as the phrase, and McEnroe's accompanying tantrum, featured in comedy sketches, TV adverts and pop songs and the man himself even used it as the title of his autobiography.

McEnroe continued to rail against the authorities throughout his career and fans came to be almost disappointed if he held his tongue and merely entertained them with some of the most sublime tennis ever produced.

Eventually, though, technology came to wield a greater influence than the human eye and courtside rows generally went the way of wooden rackets.

Back in 1981 Wimbledon fans responded to McEnroe's rant with a slow hand-clap which, in some sort of delicious irony, is now the accompaniment to the big-screen replays of line calls that have been appealed against by players as part of their three challenges per set allocation.

When once they booed a line-call query, they now cheer and clap when a challenge is successful and as "Superbrat" mellowed to become a widely-respected TV analyst of the game, memories of his behaviour attracted a rose-tinted tinge.

In a poll last year to discover their most memorable Wimbledon moment, 5,000 fans paid lip service to Briton Virginia Wade's emotional home success in 1977, the epic 2008 Roger Federer-Rafa Nadal final and even the momentous Borg-McEnroe tie break in 1980.

There was, of course, only one winner. And yes, they were being serious.