Football Manager is a game that is driven by data and statistics. From shots on target percentage to pass completion rate and dribbles made per 90 minutes, there are a wealth of metrics for you to pore over.
It’s piecing together the mathematical jigsaw at the heart of the game that fuels those late night stints spent trying to drag a team from non-league to European football’s top table, convincing yourself you’re one game away from glory.
We’ve all watched games, be it in real life or in FM, where our team has played well but still failed to win. This is a regular occurrence in football – the final score is often unreflective of the ability of the two sides.
Every judgement, opinion or prediction that we make on aspects of the beautiful game is grounded on our assessments of past performances. But how can we expect to accurately analyse the sport when it is so heavily influenced by randomness?
This is where Expected Goals steps in; a statistic that has grown in prominence within football and now makes its debut in Football Manager 2021.
What is the Expected Goals method (xG)?
The Expected Goals method offers by far the most advanced, profound and accurate gauge of footballing performance. It allows us to quantify exactly how well teams or players are performing when luck is stripped from the equation.
Before we study how we can us xG to actually analyse football, it might be worth explaining how the Expected Goals method actually came to be.
The Expected Goals method first started appearing in niche online forums in 2013. These football analysts realised that a great deal of insight could be gained from looking at the quality of attacking situations that a team was creating (and conceding), as well as the quantity of them.
Before long, bettors had caught on to this and began to use Expected Goals to take on the bookmakers. Professional gamblers used xG to develop more accurate match forecasts than the bookies, and in turn were able to turn over millions of pounds.
Professional football clubs were next to realise the power of xG. Brentford have been the leaders in this field, revolutionising their recruitment set up and using Expected Goals to identify and sign undervalued talents. Their “moneyball” style of scouting has become semi-famous and the small West London side have turned over more than £100m of transfer revenue since 2015.
Finally, the media have begun to adopt xG to provide more profound insight into their analysis with Expected Goals featuring in highlight shows and news reports.
Slowly but surely, xG is becoming more mainstream. An increasing number of people have realised the revolutionary impact that Expected Goals can have on football analysis.
How can xG be used to analyse football?
The Expected Goals method offers a statistical measure of the quality of chances. In essence, every shot which occurs in a match is given a Shot Probability – the percentage chance that a shot from that location will result in a goal.
For instance, a speculative shot from 35-yards will have an extremely low xG – let’s say, 0.02(xG). On the other hand, a tap in from very close range will have a much larger Shot Probability – in the range of 0.50-0.80(xG). Most shots fall somewhere between 0.05-0.25(xG).
There are several parameters that are used to measure the difficulty of a shot. The location of the shot is obviously incredibly important. How far out was the shot taken from? Was it taken from a tight angle? Other factors also play a part. Was the shot taken on the player’s weaker foot? Was the ball on the ground or was it bouncing? Was it a header (headers are much more difficult than shots with the feet). Were there any defenders between the shooter and the goal? Was the goalkeeper well positioned? And so on.
Sports Interactive, the team behind the Football Manager series, worked with sports analytics company SciSports to develop their own xG model that takes into account an even broader range of factors including the speed of the shot and the position of the shooter’s team-mates on the pitch.
What does this mean for Football Manager?
As previously mentioned, Football Manager players might be used to watching their team dominate matches and still end up on the losing side. Indeed, the phrase “getting FM’d” has entered the mainstream football dialogue, indicating such matches when a team loses 1-0 despite taking eighteen shots to their opponents’ two. The introduction of xG will now allow you to better quantify this bad luck so you can at least be fully informed when laying into your players after the full-time whistle.
FM21 also introduces xG match stories. These infographics display the cumulative xG that either side has accrued throughout the game, showing the flows of dominance in the match making it easy to see where things went right, or wrong for your team over the 90 minutes.
It’s not just on matchday where Expected Goals can help inform your decision-making, as xG can help identify areas of your squad you might to strengthen in the transfer window. Is your defence conceding a lot of xG? Or is your striker missing a multitude of high Shot Probability sitters? Then you know exactly where a chunk of your transfer budget will need to be spent.
Likewise, you might seek to turn to Brentford’s “moneyball” style approach in the Football Manager transfer market. Will you be able to uncover a hidden gem whose Expected Goals stats indicate that he is performing at a level far greater than his price tag might suggest?
The Expected Goals method is the most powerful indicator of footballing performance and will equip you in FM21 with the best set of tools to properly understand what is happening out on the field of play.
Football Manager 2021 is out now.
