math question

[vhdgkl]

i need to know formula for calculate how much change an odds to vary another odds

for example: i have 3 horses in a race

the fav: @2,4 the second fav: @3 the third: @4

if the fav goes to @2,6,how much should change the odds of second favourite and third?

ok,i know that the second fav should goes to 2,74 and the third remain to 4...but if all was fair,which is the formula(whit n horse)


happy new year

[cybernet69]

Depends how many horses there are in the race and how close the 4th, 5th etc odds are to the rest.

Unless you mean there are only 3 horses in the race ?

[vhdgkl]

Depends how many horses there are in the race and how close the 4th, 5th etc odds are to the rest.

Unless you mean there are only 3 horses in the race ?

n horses

formula whit n horses

thanks

[cybernet69]

Depends how many horses there are in the race and how close the 4th, 5th etc odds are to the rest.

Unless you mean there are only 3 horses in the race ?

n horses

formula whit n horses

thanks[/quot

Probably impossible to compute with any accuracy.

Its possible with 2 or 3 outcomes but not in a 12 horse race etc.

[vhdgkl]

are you sure?

i think,for example, to@5 ,more or less 20% of change

so,in a race whit 10horses to @10 and anyone go down to @5 you have 10%of book percentage to redistribute at other 9horses....1,11%for anyone..

@10 + 1,11%book percentage =@11,2(ok,11 or 11.5)..and so you will have this situation: 1horse at @5 and 9 horses at @11,2(11)


i no idea which is the exact formula for any situations
and in the same race one horse go down to @5 and another horse go down to @7,the others 8 horses?

..rather: i need a formula ..so i can calculate it in a second in any situation..in the way that i illustrated i waste 3minutes

[cybernet69]

are you sure?

i think,for example, to@5 ,more or less 20% of change

so,in a race whit 10horses to @10 and anyone go down to @5 you have 10%of book percentage to redistribute at other 9horses....1,11%for anyone..

@10 + 1,11%book percentage =@11,2(ok,11 or 11.5)..and so you will have this situation: 1horse at @5 and 9 horses at @11,2(11)


i no idea which is the exact formula for any situations
and in the same race one horse go down to @5 and another horse go down to @7,the others 8 horses?

..rather: i need a formula ..so i can calculate it in a second in any situation..in the way that i illustrated i waste 3minutes

It's just not that simple to come up with a set formula. Because the favourites odds could decrease, 2nd Fav odds could stay the same, 3rd odds could increase, 4th odds could stay the same, 5th odds could increase etc etc

Don't forget, on Betfair there isn't just one person creating a book% on a horse race plus you have different people requesting different odds.

A high street bookie will adjust the odds depending on how much liability he has per horse.

[SeaHorseRacing]

A high street bookie will adjust the odds depending on how much liability he has per horse.[/quote]

High street bookmakers taking a bet?
They only adjust there odds to a £100 bet on a odds on favourite.

Couple of years ago I couldn't get 5k on an odds on favourite.

[cybernet69]

A high street bookie will adjust the odds depending on how much liability he has per horse.

High street bookmakers taking a bet?
They only adjust there odds to a £100 bet on a odds on favourite.

Couple of years ago I couldn't get 5k on an odds on favourite.[/quote]

I think you been on the sauce mate.

Bookies take massive bets on odds on favourites all the time. Why ?, because very often the favourite gets done over.

[EyePeaSea]

A high street bookie will adjust the odds depending on how much liability he has per horse.

Yes... that's the conversation I keep having with people. Surely the bookies don't care who is actually likely to win, they just want to cover their exposure.

If a three legged Donkey was running (hopping) in the 12:15 at Cheltenham and £5m was bet on it to win, it would start off as the favourite

I'm sure I heard (on here?) years ago, that was why the Queen Mum's horses were usually lower odds than their form would warrant - so many people would bet on her horses "just because", the odds would fall, so bookies spread the risk by encouraging people to bet on other horses.

Ian

[vhdgkl]

ok..i found it..i think so

for example race whit 4horses

a)@2 b)@5 c)@5 d) @10

a change of 10%of book percentage of the fav(from 2 to 2,5)imply a change of 4%book percentage of the second and third from@5 to 4,16 and a change of 2%book percentage of the D from@10 to 8,33

anyother change imply more or less strong


formula is this,for anyone number of horses..
change,for example,@d to vary any odds of one horse(for example A from 2 to 2,5)

@d/@a 10/2=5=x1
then:
change book% indipendent variable(in this case A)/x1
(100/2-100/2,5)/x1=(50-40)/5=2=y1

y1 is the %change on the D odds

100/10(D)=10+2(y1)=12
100/12=@8,33

8,33 is the correct odds for D to vary 10%book percentage of one horse.



ok..in every case,if anyone have @10 and one horse decrease of 10%book percentage,the odds at 10 must be at 8,33 ...if more of 8,33 this horse is weak,if less 8,33 is strong..if 8,33 is normale