The expected goals statistic, commonly known as xG, is now used frequently in modern football, so what does xG actually mean?
Standing for ‘expected goals’, xG has become a widely-used phrase in modern football parlance and media. While it can be useful in some respects, other occasions show how it can sometimes be a null measurement upon which to judge a football match.
It is important to note the statistic only began to be recorded in the 2010/11 season.
What does xG mean?
1 – With an Expected Goals figure of 7.27 this evening, Liverpool recorded the highest xG total on record (since 2010-11) in a single Premier League game. Bombarded. pic.twitter.com/a0Fy24HHGz
— OptaJoe (@OptaJoe) January 1, 2024
As mentioned, xG means expected goals. It is a measurement designed to tell you how many goals a team should have scored based on the quality and quantity of their chances created.
The calibre of the goalscoring chances being created and the likelihood of them being scored are indicated by xG figures, which are added together to produce a total at the end of the match.
In theory, the statistic should mirror the result of the game, but, as we know, football isn’t played on paper.
The numbers are calculated based on severable variables, including distance from goal, the angle needed to score, how the shot is taken (eg. head or foot), and several other things that go into a computer to produce an xG rating.
Context behind the numbers
Each chance is given an xG rating between zero and one. A penalty, for example, is rated as 0.76xG, meaning the taker is expected score 76 percent of their penalties.
The closer the xG rating to one, the higher chance of a goal being the outcome. As mentioned, these numbers are then totted up throughout the game to produce an overall score.
Liverpool’s final figure vs. Newcastle in January 2024 was 7.27, meaning that, in theory, they should have scored seven goals from the quality of their chances created.
The Newcastle manager, Eddie Howe, pointed out after the match that Liverpool’s two penalties would have contributed largely to that uniquely high figure.
However, even if you were eliminate those spot-kicks, an xG of 5.75 is still very high, especially in comparison to Newcastle‘s measly 0.59!
Is xG reliable?
In general, the team with the higher xG at full time do run out winners. However, there are constantly cases of the opposite happening, which is why football can be such an exhilarating sport.
The statistic can be useful to see how well your team are creating and conceding big chances, but it isn’t a statistic to live and die on.
You also have to be careful where you find your xG stats. We’ve used Opta for this, but there are often less-than-reliable figures that circulate on the internet.