What is xG in Football?
Picture this: It's the 90th minute of a crucial match. Your team has taken 25 shots but hasn't scored. The opposition has had just one shot and scored. The commentator says, "That's football for you." But is it really just luck?
Expected Goals (xG) is a statistical metric that measures the quality of a shot based on several variables. In simple terms, xG tells you how likely a shot is to result in a goal, expressed as a number between 0 and 1. For example, a penalty has an xG of around 0.76, meaning it has a 76% chance of being scored.
Born in the early 2010s through the work of analytics pioneers like Ted Knutson and StatsBomb, xG emerged from a growing movement of statisticians who believed football deserved better than "that's just football." While shot location models existed earlier, modern xG as we know it today took shape around 2012-2014 when more sophisticated models began incorporating multiple variables beyond just shot location.
How is xG Calculated?
Expected Goals (xG) assigns a probability (from 0 to 1) to each shot, representing how likely it is to result in a goal based on historical data from thousands of similar situations.
Distance from goal
The most influential factor
Angle to goal
Wider angles reduce xG significantly
Body part used
Foot, head, or other
Type of assist
Through ball, cross, cutback, etc.
Pattern of play
Set piece, counter-attack, possession
Defensive pressure
When available in tracking data
See xG Explained
Video: Tifo Football's excellent explanation of what xG means in football