Maths help, percentage calculation on decimals

Ultra_Extreme

Ultra_Extreme

Ultra_Extreme

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Hi guys, if any of you into your maths you might be able to help me and some friends with a probability dilemma. We want to set a spread sheet up to calculate probability versus risk. I will try to explain as best i can and maybe someone can help me with a formula.

This involves betting on sport, for those who dont know anything about exchange betting i will give an overview. On a betting exchange you can both back and lay the outcome of an event in real time. This means you can bet on and against an event, this allows you to trade a bet much like you would a share or stock on a financial market.

Now lets say you back an event at decimal 1.5 (1/2) for £100, you have a potential win of £50 versus a loss of £100. If you then lay this bet off at 1.33 you risk £33 of your win to return £100, this would leave you with a potential win of £17 on your initial outcome or no-loss on the opposite outcome.

Most people involved in trading however would 'arb' this bet. By laying slightly more than your first stake to gain even profit on all outcomes. For example in the above case you could lay at 1.33 for £112.78 which would mean you win £12.78 no matter what happens.

Obviously this works the other way to and you need to do the same if exiting for a loss. If you backed the same 1.5 for £100 and layed at an exit of 2.2 then you would need to lay £68.18 for a level loss on all outcomes of -£31.81.

If you're with me so far then great! Because here is where i run out of my own maths and need the help!

In excel i need to be able to plug in the odds im backing, the odds i want to exit for profit and the odds i want to exit for loss. I then need the spreadsheet to calculate the break even, that is how many losses can be accepted per win, so if average win was 60 and loss was 20 then would be 3/1 (decimal 4.0)

Im sorry i cant be clearer than that ive done my best, can anyone help?
 
Not entirely sure what your asking but if the title really does describe the problem.

1% of a decimal is the same as 1% of anything ie x/100

so if your decimal is 0.25 1% is 0.0025 and any percentage is just a multiple of that.

For your last formula whats wrong with wins/loses + 1
 
I came in here to mock you based upon the thread title and what I thought was a very easily understood concept.

Imagine my surprise when it turns out that I'm the dumbass :o
 
If you have 2 odds you want to arbitrage then think about it this way.

Security A gives you +50 or -100 for one of two outcomes.
Security B gives you -33 or +100 for the the same outcomes.

You can buy any proportion of each security you wish. Let's say p and 1-p for A and B respectively.

You need income given either outcome to be equal.

50p - 33(1-p) = -100p + 100(1-p)

150p = 133(1-p) = 133 - 133p

p = 133/283

---------------

I hope this is right lol.

edit:

completely irrelevant to your question :(

good night :p
 
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ok one more bit of help needed if possible, if i have winning hedge A and losing hedge B (negative) how can i ask a cell to tell me what % of A, B is?

EDIT so for example lets say winning hedge is 50 and losing hedge is minus 25, i would like the cell to output 50%
 
Not sure on quite what your asking again sorry.

give me the numbers you need looking at I might find it easier, though *-1 will convert a negative to a positive if that helps.
 
Alphane said:
Not sure on quite what your asking again sorry.

give me the numbers you need looking at I might find it easier, though *-1 will convert a negative to a positive if that helps.
Click to expand...

thanks that does help.what im trying to do is get a percent from the result of win / loss the aim would be to represent the loss as a percentage of the win
 
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