The Grand National, taking place later today, attracts tens of millions of pounds in bets every year.
It's estimated that a quarter of British adults bet on the race, and that the majority of these gamble their money on little more than the name of the horse.
According to the Grand National Statistics website, people bet on a variety of different factors, most relating to the physical appearance or name of the horse:
47.4 per cent because of horse name;
19.4 per cent because of horse colour;
19 per cent because of jockey number;
and 7.3 per cent because of a jockey.
But what are the patterns seen among the previous winners of the Grand National? Do any of these factors actually influence whether a horse will go on to glory?
We've crunched the numbers to see how a horse's names, age, weight and more can hint at whether they are tipped for success.
Should you bet on the favourite on the day?
Many novice punters on the Grand National know very little about horse racing and instead rely on betting odds to make their choice. They may decide to place their bets on the bookie's favourites, which currently are Vieux Lion Rouge (10/1) and Definitly Red (11/1).
But this may not be wise. 16 per cent of Grand National races have ended up with the favourite winning - around one in six.
This is since 1839, which is seen as the first official running of the Grand National at the Grand Liverpool Steeplechase. The favourite, Lottery, won this race.
Excluding the one race in the 1830s, the 1890s was the decade which saw the highest proportion of races dominated by the favourite - with half of its ten Grand Nationals being won by the favourite horse.
Red horses have performed better in the past
The Grand National has been won five times by horses with 'Red' in their name: Red Alligator in 1968, Red Marauder in 2001 and Red Rum in 1973, 1974 and 1977.
Three 'Silver' horses have won the race, while just one 'Gold' and one 'Teal' horse has taken first place.
So if you're thinking of choosing your horse based on its colour, red might well be lucky for you. Definitly Red, currently with odds of 10/1, could see the colour-based dominance continue.
Pick a horse beginning with the letter 'R'
Driven in part by the success of 'Red' horses in the 169 Grand Nationals to date, 20 have been won by a horse with a name beginning with 'R'.
The last of these was Rule The World, who won the race in 2016, while the first was Reugny in 1874.
'M' is the second most successful letter to be at the start of the winning horse's name, followed by 'S', 'A' and 'C'.
Don't pick your horse with a human name
Human names in the horse's name h as influenced many bets in the Grand National, with people often picking horses based on kids' or family members' names.
According to research by Coral, one in five British adults said they would pick a horse based on a name that means something to them - such as a person's name.
But these millions of pounds may be misspent, if we look at the previous winners of the race. Just a quarter of winners have had a human name, at 39 horses altogether.
This is based on the most recent data from the ONS on baby names, which includes common names such as Joe alongside more unusual names such as Red and Royal.
Horses with human names to race this year include One For Arthur (14/1) and Drop Out Joe (66/1).
Nine-year old horses perform well
If you're looking for a more precise way of picking a horse for the Grand National, the age and weight of a horse are proven statistics that can help pick out a winner.
Based on the age of previous winners, the peak age for a horse to win the Grand National is 8.8 years old.
46 winning horses - just over a quarter of the total - were aged nine, with five being the age of the youngest winner and Peter Simple, aged 15, being the oldest winner in 1853.
It's no surprise that horses that aren't too old or young do better in the race: stamina and jumping ability are essential for the Grand National. While younger horses tend to have more speed than stamina, older horses are often past their prime needed to pass the National's many hurdles.
Of the 40 horses taking part in the race, 17 horses are aged nine, including several of the favourites.
When they carry less weight
Age is only part of the equation though - with the weight carried by the horse proving as, if not more, important.
Since World War Two, only seven Grand Nationals have been won by horses carrying more than 11st 5 lbs - two of which were by the famed Red Rum.
Another one of these wins was in 2015, when Many Clouds carried 11st 9lb as he rode to victory.
The Grand National is a handicap chase, which means that all horses carry weights - with the faster horses carrying more weight in order to make the race "as even as possible" with all horses having "an even chance of winning".
This means that horses carrying more than 11 stone 6lbs have often struggled, although there is speculation that recent changes to the race could help horses with high weights a bit more.
Since 1839, the average weight carried by a Grand National winner is 10 st 12 lbs.