Using a normal Poisson distribution to estimate xG in the Bundesliga

Below we use a normal Poisson probability distribution to estimate the Total Number of Goals in five games in the Bundeslia on Saturday May 30th.

To determine xG we use the following equation:

xG is derived from the o2.5 goals price. That price is taken as:

  • The Last Price Matched on the Exchange, as long as this is still between the available Back and Lay prices, otherwise
  • The Bet365 o2.5 price + markup

The equation above was built up from an analysis of 40,000 games in UK and Europe.

Using this equation we get the following xG for each game:

The total xG for the Bundesliga is expected to be 16.11 goals. This compares with an xG of 16.05 from the mid-points of the SportingIndex markets.

We can further reality check by looking at the Wisdom of the Crowds on a liquid market on Betfair Exchange.

By using a normal Poisson distribution we can look at a comparison of the available prices on the exchange vs the estimated odds using bookiebashing xG and spreads xG.