In the nervy final moments before the start of the Grand National, no trainer in the race will have a better idea than Nigel Twiston-Davies of what it takes to land the most famous prize in horse racing.
Bindaree won a thrilling duel with What's Up Boys in 2002
To train one National winner is a landmark achievement. But to do it twice - with different horses - puts you in a different league.
The Cotswolds handler's successes with Earth Summit (1998) and Bindaree (2002) cannot be matched by anyone else currently training National Hunt horses.
So Twiston-Davies's thoughts on what makes a good Grand National contender are worth listening to.
The key ingredients, he says, are that the horse stays a long trip and is a solid jumper.
"If horses are from good jumping families they often have staying blood in them," he told BBC Sport.
"But there have been a whole variety really. You think of those that have been tiny and others that have been big.
"Everybody does everything their own way and there's no specific way to train a Grand National winner.
"Winning the race twice has been great but no-one can go without the horse and they were both very, very clever and athletic horses - both precise jumpers and, in Bindaree's case, very very, powerful."
Having started training in 1981, Twiston-Davies's stable had, by the turn of the millennium, developed a slightly unfair reputation for producing sparkling early season winners before fading away.
By early 2002, he had been preparing to quit the sport altogether until Bindaree's victory at Aintree gave him a second lease of life.
The past few years have been some of the most fruitful of his career and at the age of 50, his enthusiasm for the sport has been thoroughly restored.
Though he has five runners for this year's race, Twiston-Davies does not like to start preparing a horse too early for Grand National day.
"Towards the end of January you assess how things are going. If horses have been running well in long-distances races we enter them at the end of January," he said.
"It's very similar to the Cheltenham Festival. We don't do anything very different, we just lay them out for the race.
"It's not rocket science, we just try to get them fit and well for the day."
Carl Llewellyn rode Earth Summit, Twiston-Davies's 1998 winner
The range of weights determined by the handicappers is less of an issue these days.
"The weights have been quite compressed in recent times," he said.
"When the top weight carried 12 stone and the bottom weight 10 stone that made a lot of difference, but it's not so much now."
But the specific demands of Aintree's famous birch fences are a serious factor, while he admits a horse needs more luck in the Grand National than any other race.
"There are more fences to be jumped and more horses than in any other race," he said.
"In the race things can go wrong. We've been very lucky and have had a lot of very fair runs round here but afterwards there will be a lot of hard-luck stories. Hopefully none of them will be ours."
Twiston-Davies on his previous Grand National winners
"The Grand National is a very long race but we really couldn't believe it with Earth Summit because he won quite easily.
"I didn't know he was going to jump as well as he did round here because he had always been quite a careful horse and I thought the big fences might frighten him to death.
"But he just took to it like a duck to water and you could see he was going to win from a long way out so it wasn't too nerve-wracking.
"In Bindaree's race I was watching with Philip Hobbs who was training What's Up Boys.
"First of all Phillip's horse was in front, then Bindaree, then What's Up Boys and then Bindaree.
Ollie Magern is minuscule but jumps like a bunny
Twiston-Davies on one of his five chances this year
"It was very anxious but Bindaree was carrying a lot less weight and just outstayed the other horse.
"There was a lot of laughing and shouting and screaming because Phillip and I are great mates.
"I don't let him forget about it to this day because he stays for Cheltenham and when he's having breakfast he watches Bindaree grazing in the field out of the window so I wind him up about it then."
Is Donald McCain's entry Cloudy Lane a worthy favourite?
"He's run very well and is very much a worthy favourite. But he's still got to jump round, and he's got to persuade other horses not to fall in front of him or knock him over.
"I've got a bit more of a chance because I've got five in the race, so hopefully one of them will have a free run.
"Ollie Magern is minuscule but jumps like a bunny. Knowhere is very, very big but has got quite a lot of weight.
"Fundamentalist has done nothing wrong this season and Naunton Brook really enjoyed it round here last year for a circuit although he didn't finish. We need to get him going steadier this year. Ardaghey's also a very good horse."