To be a successful punter in soccer betting, you should intelligently guess two main things: the probability of a win and the size of the stake. Online betting tips and team news can help you to estimate the probability of a win, but choosing the stake size is a more complicated task that requires each punter to decide according to his individual betting strategy.
This article summarizes a research intended to optimize the use of Kelly strategy, the most profitable of all the existing betting strategies. The research is based on a comparison between statistics of betting profits of top European soccer leagues that played during 2008/09 and those playing in 2009/10 seasons.
Data and Methods
- The research was conducted based on match results and average betting odds from 60+ bookmakers taken from the following European Soccer leagues: Austrian Bundesliga, English Premier, Dutch Eredivisie, French Ligue 1, German Bundesliga 1, Greek Ethniki Katigoria, Italian Serie A, Scottish Premier, Spanish Primera Division and Turkish Super Lig.
- Each match outcome receives its own value defined by multiplication: odds x probability of a win. When this value is higher than one, it is considered as a “value bet”.
- The probability of home win/draw/away wins in this research is defined by the frequency of their appearance in a national tournament.
- According to Kelly’s strategy, the wager for each outcome is calculated as follows: w * (p-(1-p)/(odds-1)) (w represents the wealth of the punter and p is the probability of a win). For example, if your wealth is 1000$, p is 50% and the odds are 2.5, then the preferable wager is equal to 1000$*(0.5 – 0.5/(2.5-1))=166$
- The punter’s profit is calculated by assuming he places a wager according to the Kelly’s strategy for those outcomes whose value is the closest to the value bet defined a priory.
- An optimal value bet is a bet resulting in a maximal profit for a punter.
According to the research, the optimal value bet for soccer betting is 1.37 (2009) compared to 1.39 (2008). The betting profit of a punter who uses Kelly’s strategy with these optimal value bets is equal to 10% in 2008 and 14% in 2009. The results show that when a punter uses Kelly’s strategy placing bets on the outcomes with an average value bet of 1.38, the betting profits will be maximal. High quality betting tips can increase the profits dramatically but the optimal value bets have to be recalculated to adapt them to the accuracy of your betting tips.