Expected Goals (xGs)
Football has come a long way in terms of analysis. Back in the days, football statistics were usually limited to the number of shots, shots on target, passes attempted and completed and so on. These days, new metric systems are coming up that provides us with greater insight into the game. These new metric systems allow easy scouting of players with specific attributes, accurate assessment of player performances, and even analysing your opponent’s strengths and weaknesses. Expected goals (xGs), expected assists (xA), expected goals on target (xGOT), key passes, chance created, take-ons, among others, are examples of data that is being collected. The one of much importance that is related to this article is the xGs.
According to Opta, xGs measures the quality of a shot; this means xGs shows the number of goals a team or a player could have scored. The quality of the shot will depend on many factors before it is rated between 0.0 to 1.0. Such factors include shot angle, distance to goal, the type of pass, among others. Particularly, xGs can also determine the quality of a chance. A high-quality chance will most likely be converted into a goal and hence will have a high xGs.
When a team wins a match by 2-0 and their xGs is 4.8, it clearly shows that the team could have scored more than the two and were probably unlucky not to have converted those chances. Similarly, when a team wins by 2-0 and had an xGs of 0.5, one can say that the goal scorers are very efficient and will most likely convert a low-quality chance to a goal. It also shows that the chance creators could not create any better chance for their team to have clear cut goal scoring opportunities.
xGs is important in modern football; besides the importance already listed, a team can use this data to find their most efficient goalscorers. More about xGs and other metric data will be available on our youTube channel soon, together with videos to provide more understanding.