[waealu]

In decimal soccer odds, the probability of success is 1/(decimal odds).

For example, in a game on 12/10/11, Sportsbook.com has the money line for a game:
Southampton (1.60)
Blackpool (5.75)
Tie (3.50)

Using the first equation, the probabilities of each success is as follows:
Southampton 62.5%
Blackpool 17.4%
Tie 28.6%

However, the summation of these probabilities is 108.5% Why is the summation of the probabilities more than 100%? Are my calculations correct or else, what causes this discrepancy?

Thank you!

[The Special One]

essentially the bookie is scamming you on that 8.5%... if you were to bet proportionally based on those percentages, you would guarantee an 8.5% loss

bet $62.5 on 1.6 = $100
bet 17.4 on 5.75 = 100
bet 28.6 on 3.5 = 100

however, you spend 62.5+17.4+28.6 which is $108.5... so you spend 108.5 to win back 100, $8.5 less in your account... this way the bookie is ensuring that you lose money if you try to bet ANY GAME without losing FOR SURE..

the odds given are significantly deflated... assume Southampton gets 1.6, that means a 62.5% chance of success...
with that, Blackpool winning should be 14.1% and DRAW 23.4% - the bookie overestimates those 2 possibilities...
given the new (correct) %s, odds should be:

1.6, 4.2, 7.1

- now imagine millions of dollars being bet on this game... on average the bookie would guarantee an 8.5% profit, UNLESS (rarely) most people bet on only 1 option..