Backing the Melbourne Cup favourite: Are the odds in your favour?
It's that time of year again, when Australians who know anything and nothing about racing stop what they're doing for the Melbourne Cup.
ABC Fact Check takes a look at the statistics since 1861, the very first year the Melbourne Cup was held.
How often does the favourite actually win? And would you be ahead or behind if you bet on the favourite every year?
Here's what we found:
1.
A favourite horse has won the Melbourne Cup 34 times out of 153 races. This means the favourite has a 22 per cent chance of winning.
Peter Hall, a professor in mathematics and statistics from the University of Melbourne, says that's a good result.
"If you choose a horse at random, the probability that it wins is 1/24 = 0.042; and if you put your money on the favourite, the probability of it winning is 34/153 = 0.22," he said.
"That's an increase by a factor of about 5.3 by simply noting which horse is the favourite, and that is not bad."
2.
The favourite has placed first, second or third in 46 per cent of all Melbourne Cup races.
3.
The favourite's odds have ranged from $1.73 - Phar Lap in 1930 - to $8. The winner's odds have ranged from $1.73 to $101.
Veteran racing journalist Max Presnell says there will never be another favourite with odds as short as Phar Lap's.
"The composition of the Melbourne Cup has changed with the internationals racing in it, it's a handicap, horses carry big weights, so it would be very surprising if another champion like Phar Lap ever raced in a Melbourne cup," he said.
"The great horses these days will shy clear of it... they wouldn't want to risk a good horse to win one race."
4.
The average odds of all Melbourne Cup favourites is $5.03.There have been 173 favourites since 1861 - two equal favourites 16 times, and three equal favourites twice. The average odds of all 153 winners is $15.25.
5.
If you had put $10 on all 173 favourites to win in every one of the 153 Melbourne Cup races, you would be behind by $20. The total winnings from the 34 favourites that won would have been $1,710, but you would have spent $1,730.
6.
The longest period without a favourite winning is 13 years, before Bitalli broke the drought in 1923.
A favourite has never won the Melbourne Cup more than two years in a row. British-bred Makybe Diva is the only horse to have won the Melbourne Cup three years in a row in 2003, 2004 and 2005, but she was only favourite in 2004 and 2005.
7.
Only two horses have been the Melbourne Cup favourite three years in a row. Trafalgar in 1909, 1910 and 1911, who didn't win in any of those years, and Phar Lap in 1929, 1930 and 1931, who won in 1930.
8.
The last Australian-bred favourite was Alcopop in 2009. The last Australian-bred favourite to win the Melbourne Cup was Sirius in 1944. The last Australian-bred horse to win the Melbourne Cup was Shocking in 2009.
"The visiting horses are better stayers than our horses, they're better over longer journeys - the 3,200 metres - than our horses," Presnell said.
"They've got to travel over here and settle in and handle our conditions, which for years was a problem, but they're getting better at it now because the trainers understand what they've got to do, so it's becoming very hard for Australians to win the Melbourne Cup."
9.
In 1934, equal favourites Nightly and Sir Simper had a starting price of $5.50 but finished 21st and 22nd in a field of 22.
