What is 'Standard Deviation'?
Standard deviation is a measure mainly used by statisticians to determine the estimated volatility of a set of data or predictions. In other words, it's how far you would expect any one outcome to differ from the average. In gambling
it can give you a helpful idea of how much to expect a set of real results to vary from their statistical average.
'Standard Deviation' Explained
Standard deviation could be seen as the amount any given result will deviate from the statistical average. It can be particularly useful in sports betting
to work out how predictable or volatile a set of unknown outcomes, such as scores, might be, based on past performance.For example, in football, the average number of goals scored per team in any matchweek might be 2. Standard deviation tells us how far either side of this average the real results can be expected to reach. To work out the standard deviation of goals per team in a league of 20 teams, you would need to:
- Subtract our average (2) from each team's goal tally for a given matchweek, to see how far from the average it deviates
- Take the square of this number, for each team
- Add up all these square numbers to give us 108
- Divide this total by the number of teams (20) and subtract 1, to give us 4.4
- The standard deviation is the square root of this figure - 2.09
Armed now with the standard deviation as well as the average, you have a much clearer picture of the distribution of goals throughout the league. If this were combined with data from multiple matchweeks, you would be able to estimate with even more accuracy the future goal tallies of the teams in the league.