Yield (ROI = Return Of Investment) issue

[Ivica TypeR]

The Calculation of simple yield:

The Return*
(Winnings)
__________ X 100= ROI (%)

Investment*
(Stakes)


so for example: I have 1000 bets with odds 2,00
500 of them are winning and 500 losing. So i am on 0 and my ROI is zero

Would like to get right odds to have 15% yield,
How to calculate on what odds should i be to have ROI 15% ?
Because odds are not always 2,00 - they are different but i gave 2,00 as
example...

So, i know what are odds to have 0% yield, but would like to get with
some formula odds to have 15% yield (ROI)!?

Thanks very much for help!
Ivica

 

[Bernie Deitrick]

Ivica,

Actually, the formula is

(Winnings/Stakes -1 ) * 100 = ROI

No matter what the odds are, on average, you will break even, if the betting system is completely
fair. Usually, the system isn't fair, and you have less than a 50% chance at best (like in
roulette, if you bet black, the odds aren't 1 to 1, they are 1.111 to 1 against winning, which is
the house edge). So, there is no odds system that will give a positive rate of return over the long
run.... Games of skill, like poker, can allow some players to have a positive yield, but overall,
once the house takes its cut, the average yield is still negative. That is a hard lesson for many
gamblers....

HTH,
Bernie
MS Excel MVP

 

[Ivica TypeR]

Hi Bernie,
don't worry about breaking even and house cuts.. That's why i am mostly
on betting exchanges (places where people bet against each other so
there are some values..)
I'm too long in betting and earn some nice amount of money in past,
and believe me, you can't line sports betting with roulette where
mathematically there is no chance of success and odds are always in
house favor! In sports betting house can mistake with their odds while
on roulette everything is always same..

Anyway, i received one answer on some forum with some solution which
should get into excel formula, but don't understand it all, so maybe
someone could explain it easier:


Let p = 1/odds be the probability of success, and R = 2 be the amount
you win on a success (as a multiple of the amount you put down). Suppose
you play n games, where n is large (in your case n = 1000, but it
doesn't really matter).

Expected winnings are npR, and expected cost is n. ROI is (npR - n)/n =
pR - 1.

If you want ROI to be 0.15, just solve pR - 1 = 0.15. If R is fixed at
2.00, solve 2p - 1 = 0.15.