Sportsbooks’ edge may surprise some So, what are we looking at when it comes to a sports
pg bet? Looking at something simple like the FA Cup Semi Final between Tottenham Hotspur and Manchester United (21st April). A market with two simple outcomes like who will qualify for the Final see Bet365 offering odds of 8/15 for Spurs and 11/8 for United. The implied probability for a Spurs win is 65.2% and the implied probability for United’s win is 42.1%. The percentage adds up to 107.3%. This 7.3% amount over 100 is known as the “overround” in bookmaking terms, which is effectively the profit the bookie expects to make on the market. Without getting into the mathematics behind the margins, you can see that the relative house edge for bookmaking can be higher than roulette. Before you go rushing to close your bookmaker account, you must also remember that predicting sports’ outcomes is more scientific than the pure chance of roulette. For example, we know that the last time Spurs and United clashed at Wembley, the former won the match 2-0. This is an indicator for the outcome of the semi final, whereas if red was the last outcome in a roulette game it would have no bearing at all on what the next result will be.