horse racing

[vicious_sid]

out of idle curiosity - isn't it always - How do bookies make the odds on a race

Are there any sites that tell me how?

[ELVIS68]

They go through the runners and price up their chances of winning..ie If a horse is 5/1,basically it means it will win 1out of 5 races, 10/1 it`ll win 1 out of 10 races etc

Although the odds do shorten if there is lots of money bet on one particular horse on the day, therefore they up the prices of the others, to balance the books so to speak

One thing though, you never see a poor bookie

[Quizmonster]

It's a common misconception that 5/1 means a horse should be expected to win one race in every five, but what it actually means is this...if this exact race were to be run six times, this particular horse would win just one of them and lose five (5 + 1 = 6). Similarly, if you are throwing a die and hoping for a 6, there are five faces that are 'wrong' and only one face that is 'right', so the odds of getting that 6 are 5 to 1 against.
Bookmakers' 'books' are invariably what is called 'over-round'. Based on what is known about it - breeding, past performances, jockey, trainer, going and a host of other factors - each horse is calculated to have a percentage chance...eg 4/1 = 20% (100 divided by 4 + 1) and 9/1 = 10% (100 divided by 9 + 1). The thing is this, when all the percentages on offer are added up, they should total 100%, obviously, but they will regularly reach 120% or more. This is what enables the bookmaker to continue in business...ie he should - if he has made his book correctly - make a profit whichever horse wins.

As you can see, it is a skill that requires a massive amount of knowledge and information. But good luck in trying to acquire it, VS!

[knobbynonuts]

Elvis have you left the planet or sumfing