Posts Tagged ‘overround’

This is the formula to calculate the vigorish percentage for three-way events:

v = 100 * [(1/p + 1/q + 1/t) – 1] / (1/p + 1/q + 1/t)

Where v = vigorish, and p, q and t are the decimal payouts for each outcome.

This formula is most usefully applied to calculating the vigorish imbedded in the odds of a soccer game, where there are three result possibilities; the home win, the draw and the away win.

To see how this formula works, I thought it would be worthwhile to look at the differences in the vigorish collected by 3 different sports bet agencies for the same soccer match.

 

UEFA Champions League 18th September 2013: Manchester United v Bayer Leverkusen

TAB Sportsbet:  1.62/ 3.75/ 5.00

Sportsbet:  1.83/ 3.40/ 4.75

Bet365:  1.83/ 3.60/ 5.00

 

Using the above formula, the vig results are as follows:

TAB Sportsbet Vigorish

P = 1.62, q = 3.75, t = 5.00

v = 100 * [(1/p + 1/q + 1/t) – 1] / (1/p + 1/q + 1/t)

v = 100 * [(0.6173 + 0.2667 + 0.2) – 1] / (0.6173 + 0.2667 + 0.2)

v = 100 * [1.084 – 1] / 1.084

v = 100 * 0.07749

v = 7.75%

 

Sportsbet Vigorish

P = 1.83, q = 3.4, t = 4.75

v = 100 * [(1/p + 1/q + 1/t) – 1] / (1/p + 1/q + 1/t)

v = 100 * [(0.5464 + 0.2941 + 0.2105) – 1] / (0.5464 + 0.2941 + 0.2105)

v = 100 * [1.051 – 1] / 1.051

v = 100 * 0.04853

v = 4.85%

 

Bet365 Vigorish

P = 1.83, q = 3.60, t = 5.00

v = 100 * [(1/p + 1/q + 1/t) – 1] / (1/p + 1/q + 1/t)

v = 100 * [(0.5464 + 0.2778 + 0.2) – 1] / (0.6173 + 0.2778 + 0.2)

v = 100 * [1.0242 – 1] / 1.0242

v = 100 * 0.02363

v = 2.36%

So it is easy to see from these calculations that TAB Sportsbet is taking the most tax per bet on this game, while Bet365 is taking the least.

The other appealing figure from these odds surveyed is the 3.75 being offered for the draw by TAB Sportsbet.  If you are interested in betting on the soccer draw like I am, it would be in your interests to shop around to ensure you get the best odds for the draw on the matches you want to bet on.

The difference in odds is significant enough to warrant chasing the best price, and if you have learnt anything from the Champ Bros blog so far, you will understand that it is difficult to make a consistent profit from sports betting, so any edge you can find over the bookies will pay dividends in the long run.

The next post is going to examine the difference between Vigorish and Overround, as these terms are often interchanged incorrectly as they actually have different values.

Beaner

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