Odds change by %

[vanbuuts]

Can anyone help with the correct calculation to show the % drop in odds if odds move from 12 to 8.4 (for example).

And secondly, if I want to calculate what a 40% drop from odds of 12 what is the formula

Tad confused.

TIA

[Captain Sensible]

The maths behind percentages is simple enough but you need to decide do you want to track the percentage change between decimal odds,fractional odds or even probability?

The problem you'll find using decimal odds is you can get odds less than valid Betfair odds i.e 60% reduction of 2 gives us 0.8. So you'd generally remove your stake off decimal odds when calculating any percentage change.

So 12 going to 8.4 we'd treat as the difference divided by the starting odds minus 1 times 100 to get our percentage.

(12-8.4)/(12-1) * 100 = 32.73%


If I want a 40% drop from 12 we convert to fractional odds, ie minus 1 then multiply by our 40% drop i.e. 100-40 then add back on our stake to get a decimal odds i.e. plus 1

(12-1) * (100-40)/100 + 1 = 7.6

[vanbuuts]

Thanks for your detailed explanation. I was cross contaminating between % chance and decimal odds.

[pellleg]

TIME TODAY 16:39/UK TIME 15:39 GREYHOUND place
1 BACK 1.03 *5932.45/ Lay 177.97* 60 chance 16,67% 5
2 BACK 1.03 *5932.45/ Lay 177.97* 60 chance 16,67%
3 BACK 1.03 *5932.45/ Lay 177.97* 60 chance 16,67%
4 BACK 1.03 *5932.45/ Lay 177.97* 60 chance 16,67%
5 BACK 1.03 *5932.45/ Lay 177.97* 60 chance 16,67%
6 BACK 1.03 *5932.45/ Lay 177.97* 60 chance 16,67%
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Every day on 15-25 races sp. play
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Same thing on the winning game.
with other betting other money---------------------------------------------------------------------
You dont do this if it does not give money??
Please help me.....................

[pellleg]

Yesterday i lay on greyhound 2 hours before. Only 1 pound on the grey hounds.
Something happent. Betfair stop all bet in that race after 3 minutes .
After 15 minutes they open it..............
With gruss software and most softwares you can not se this sp betting back and lay.
I want help . I wonder if there is someone whos knows more about this.
Have a nice day