It is the annual event that has accomplished chefs quaking in their toques: Monday's 2020 edition of the Michelin restaurant guide for France reveals the winners and losers of its coveted ratings stars.

This year's edition of the so-called gastronomy "bible" caused a stir even before its official release, when it was revealed Michelin has stripped renowned chef Paul Bocuse's flagship restaurant of one of its three stars.

He died in 2018.

But Michelin boss Gwendal Poullennec defended the move by insisting stars are not "inherited", and "must be earned every year".

"We obviously understand the emotion that the loss of a star can provoke, but there is no exceptional treatment," he told AFP.

"All establishments are evaluated anonymously by our inspectors every year... whether you are an iconic chef or a young chef who takes the risk of being plunged into debt by opening a restaurant."

Almost two years to the day after the death of famed chef Paul Bocuse, Michelin revealed his iconic restaurant had lost its coveted three-star rating Almost two years to the day after the death of famed chef Paul Bocuse, Michelin revealed his iconic restaurant had lost its coveted three-star rating Photo: AFP / JEFF PACHOUD

Poullennec told AFP no other three-starred restaurants ran the risk of being downgraded in this year's guide.

According to Michelin, restaurants are selected on four criteria: the quality of the ingredients used, mastery of flavour and cooking techniques, the personality of the chef reflected in their cuisine, and lastly value for money and consistency between visits.

One star denotes "high quality cooking", two stars "excellent cooking", and three stars "exceptional cuisine".

Chef Marc Veyrat, seen celebrating after winning three Michelin stars in 2018, lost one the following year and sued the guide for suggesting, wrongly, he insists, he had used cheddar cheese in a souffle Chef Marc Veyrat, seen celebrating after winning three Michelin stars in 2018, lost one the following year and sued the guide for suggesting, wrongly, he insists, he had used cheddar cheese in a souffle Photo: AFP / JACQUES DEMARTHON

Of 30,000 restaurants listed worldwide, only about 130 have attained the highest distinction.

Critics say the process has rendered Michelin stars untenable as more and more diners baulk at spending a fortune on a meal.

The guide was born when brothers Andre and Edouard Michelin, founders of a tyre company, brought out a travel guide in 1900 to encourage motorists to take to the road and so boost business The guide was born when brothers Andre and Edouard Michelin, founders of a tyre company, brought out a travel guide in 1900 to encourage motorists to take to the road and so boost business Photo: AFP / Thierry ZOCCOLAN

A handful of French restaurateurs have in recent years relinquished their prized three-star status because of the stress of being judged by Michelin inspectors.

The 2003 suicide of three-star chef Bernard Loiseau was linked, among other reasons, to speculation that his restaurant was about to lose its three-star status.

Last year, Michelin downgraded three three-starred restaurants: the Auberge de L'Ill in Alsace, which held the highest accolade for half a century, Pascal Barbot's Parisian restaurant l'Astrance, and Marc Veyrat's Alpine restaurant the Maison des Bois, which was awarded its third star just a year earlier.

Veyrat sued the guide for suggesting -- wrongly, he insists -- that he had used cheddar cheese in a souffle.

His lawsuit was rejected.

The guide was born in a very different guise, when brothers Andre and Edouard Michelin, founders of the eponymous tyre company, brought out a travel guide in 1900 to encourage motorists to take to the road and so boost business.

There were fewer than 3,000 cars in France at the time.

Initially free, the red guidebook included maps, a how-to on changing tyres and lists of petrol stops, mechanics, hotels and eateries along the route.

The first run of 35,000 copies was such a success that guides for Belgium, Germany, Portugal and Spain followed.

The three-star ranking for restaurants was introduced in 1931.

In 2005, the Michelin Guide branched out of Europe with a New York guide, followed in 2007 by editions for San Francisco then Las Vegas and Los Angeles.

It moved to Asia with a Tokyo version in 2008 when 90,000 copies, in English and Japanese, flew off the shelves in 48 hours.

More than 30 million Michelin Guides have been sold, according to its website.