Election Odds and Probabilities

Some election odds from a bookmaker have been released on the forthcoming election for St Helier 3/4.

Being a mathematician, and not used to the strange world of gambling, I wanted to convert these to probabilities, expressed as percentage likelihood, as that is something I understand better than odds of 7 to 6. That may be all well and good if you are betting, but how do us non-gamblers tell the difference between 7/2 and 6/4 for example, and how far they differ.

Fortunately, there is a simple formula - seen at the top of this blog, which does just that. So here are the odds for the gambling types, and in an easier to see as a single ranked number (in my humble opinion) the mathematical conversion.

Anthony Lewis 11/10	47.62%
Inna Gardiner 6/4	40.00%
Lyndsay Feltham 7/2	22.22%
John Baker 9/2	18.18%
Andea Mallett 8/1	11.11%
Francesca Ahier 8/1	11.11%
Guy de Faye 20/1	4.76%
Gordon Troy 20/1	4.76%
Nick Le Cornu 25/1	3.85%
Geraint Jennings 33/1	2.94%

Incidentally, the percentages total more that 100% which is significant.

This is the "bookie's edge".

If it is under 100% it is a "sure bet" for the gambler

If it is more than 100% then it means bookie is making money on overall population of gamblers. They are also mitigating their risk (on average they win but there is volatility) of loss on a single event by modifying the odds based on the bets they have received so far as time gets nearer to the event.