Bookmakers have never been as apprehensive about the first day of a big meeting as they are to the opening skirmish at Cheltenham on Tuesday.

The layers anticipate being on the ropes at the end of round one if all four Willie Mullins-trained hotpots, ridden by Ruby Walsh, do the business in their respective races.

So pessimistic are they, that it would rate as a result if just one of the quartet was beaten. If two failed to deliver then bookmakers would be in dreamland.

Striking first blood can be crucial and that phrase was never more relevant than it is for the Sky Bet Supreme Novices' Hurdle in which the Mullins runner Douvan is around a 7-4 shot.

Remarkably he is the longest-priced of the four Mullins 'bankers' on day one. Un De Sceaux and Annie Power are odds-on for the Racing Post Arkle Trophy and OLBG Mares' Hurdle respectively, while Faugheen is not much bigger than evens for the biggest prize on the card, the Stan James Champion Hurdle.

Coral will take whatever happens on the chin.

"I don't think any of us can remember one trainer and jockey combination teaming up with four such strong favourites in one day and clearly all four are going to be very popular and will be in thousands of accumulators," said spokesman David Stevens.

"The school of thought is they all can't win, but they can. They are all favourites for a reason - they either have the form in the book or come with strong reputations.

"Anything less than a treble for Mullins and Walsh we would probably take now. One or two winners and we would snatch your hand off.

"Three favourites, whoever they are trained by is bad, but the same combination just enhances the threat we face.

"If all four were to win then we'd be looking at one of the worst Festival days for many years and that's without thinking what might happen in the other races.

"But it is Cheltenham and it is not easy. If we are going to have a nightmare day, day one would be the best. It gives us three days of trying to get it back. It is the biggest betting week of the year, no question.

"It is a proper old-fashioned battle between punters and bookies. Wherever we are after day one we will come back and start again."

William Hill are preparing for what they feel could be the worst day in Cheltenham Festival history and dread a total payout of £17million.

"It could be one of the worst days in bookmaking history if the 'Four Horses of the Apocalypse' all win. In fact we could see some 'Willie Mullionaires' by Tuesday evening," said Jon Ivan-Duke.

For once it is Walsh that Ladbrokes fear and not Tony McCoy.

"The Ruby Walsh acca has the potential to do untold damage," said David Williams.

"It's going to be the most popular accumulator bet we've ever known. If all four horses win we'll never have known a day like it at Cheltenham. It could run to tens of millions of pounds.

"We'll be desperate to see one of them beaten. Anything more than that will be a luxury, but we dare not dream. We simply want to get through the opening day in one piece and there's no guarantee it will happen."

Paddy Power just hopes to avoid what could potentially be the worse day in the company's history.

"'Black Friday' two years ago was the worst day at the Cheltenham Festival in the history of the company with four favourites winning, each of them bad results in their own right let alone the multiple mayhem which ensued," said Power.

"But that really could be a drop in the ocean if all of Willie Mullins's good things oblige on Tuesday, especially with our money back as a free bet if Douvan and Un De Sceaux win offers.

"Saying that, just as the horses need plenty of stamina to get up that gruelling hill, the Festival is a marathon, not a sprint, and the other three days will give the bookies plenty of time to recoup the potential losses."