Creating your own prices.

[wb]

How do you compile a set of odds for a race.

I want to create my own odds for a horses chance (betfair odds)

basically, I have a numerical value for each horse, and the higher the number, the more likely the horse is to win. For example:

Horse A: 75.80
Horse B: 55.20
Horse C: 40.10

As you can see, horse A has the highest chance of winning, but how do i convert this into its odds value (to a true 100% book)

thanks

[presto]

not sure, but i think RSB can do this. pricey though.

[wb]

I thought there would be a simple way of doing it.

Using an easy example.

Horse A: 100
Horse B: 50
Horse C: 50

Horse A has twice as much chance as winning, so he would be Even money, the other two would both be 2/1. Is this correct?

[Micky T]

How do you compile a set of odds for a race.

I want to create my own odds for a horses chance (betfair odds)

basically, I have a numerical value for each horse, and the higher the number, the more likely the horse is to win. For example:

Horse A: 75.80
Horse B: 55.20
Horse C: 40.10

As you can see, horse A has the highest chance of winning, but how do i convert this into its odds value (to a true 100% book)

thanks

Try adding them all together
75.8 + 55.20 + 40.10 = 171.10

100/171.10 = 0.584453535

HORSE A 0.584453535 x A(75.8) = 44.30
HORSE B 0.584453535 X B (55.20) = 32.26
HORSE C 0.584453535 X C (40.10) = 23.44

Hope thats what you where after.

[presto]

what you want to do is allocate a % chance to each runner in a race, so in your example:

100 = 50%
50 = 25%
50 = 25%

so yes
eve
2/1
2/1

.......................................................

but in a 'real' race it will not be so simple. so you will have to allocate a % to quite a few selections (make sure it add's up to 100%). this is very self opinuated aswell, that is why it is probably better to use statistical data and maybe excel to come up with the percentages for you. from this % data you should quite easily be able to turn it into odd's for each horse.

if you have ratings for each horse, you will have to find a way of turning these rating's into a %.

the example:

horse 1 - 100
horse 2 - 50
horse 3 - 50

would be easy to turn into a %. as alltogether the ratings add up to 200 so in order to get a % we must divide by 2. to get it to a %.

edit: use the method micky said

[mathare]

In your example of 3 horses they should all be 2/1 to start with. If each horse were equal they would all have the same chance of winning and 1 in 3 is 2/1.

But here Horse A is twice as good as Horse B and Horse C so the odds need to shorten on A and lengthen on B and C

[presto]

:rolleyes: - what micky said

for a moment then i completely forgot how to work out percentages

[Onlyforfun]

The only truly effective way is to determine each horses % chance. Converting raw ratings into prices is a bit iffy. However, if they were tested over enough runners you could work out the % chance of winning of a 75.8 rated runner.

To do a simple conversion you could take the rating / total ratings to give a rough %. So in the 3 horse race you have 75.8/(75.8+55.2+40.1) = 44.3%.

To get odds from this you simply divide 1 by 44.3% = 2.26 (includes stake) or approx. 5/4. What these odds mean is that if the horse selected at those odds loses 44.3% of the time youbreak even.

But like I say, its iffy unless your numerical values are heavily based on comparative factors rather than absolutes. (by this I mean, has horse A beaten horse B, rather than if has won on good gets 10pts).

[wb]

thanks everyone. Im not using RP or officail ratings, for this. The horses chances of winning are the product of a fairly complex spreadsheet with lots of variables, and represent what my systems reckons are the 'true' numerical chances of the horses winning.

The reason I asked, is to try find some more value when laying. (my own lays, not the pro-lays)
As I said, If I am going to trust my spreadsheet, I can't just lay at any given price, I have to know in betfair odds what good value is instead of just taking the best lay price on offer. I could leave offers under 'my' prices, and if they get matched, then that represents value for me

The % is probrally the best way to do this, then round it down to its nearset betfair price.

Thanks.

As ever, you are a helpful lot:)