If anyone is familiar with the Brentford P1ss take on LFW's about the games that they've won comfortably won using the xG method of scoring, whatever that is, but IRL have only drawn or lost games....... Well at the moment under xG they are beating Bournemouth 3-0 at HT, except IRL it's actually 0-0........
EXPECTED GOALS EXPLAINED: WHAT DOES XG MEAN?
When referring to football, the term xG stands for ‘expected goals’. Simply put, xG is a metric that calculates the probability of a certain shot resulting in a goal.
Looking at a historical data set of shots taken from different positions and which of those resulted in a goal, expected goals shows us how many goals an average team could be expected to score from their shots.
An xG of 1.00, for example, indicates a guaranteed goal, which obviously doesn’t exist. A goalscoring chance with an xG of 0.40 meanwhile, tells us that if that shot was taken 10 times, you could expect it to hit the back of the net on four occasions.
EXPECTED GOALS EXPLAINED: HOW IS XG CALCULATED?
As we now know, expected goals measures the quality of goalscoring chances and the likelihood of them being scored – but how is it calculated?
Despite what some may have you believe, it’s actually quite simple. The quality of a shot is measured based on a number of variables, all of which should be pretty self-explanatory to any discerning football fan.
These include:
- Assist type
- Shot angle
- Distance from goal
- Was it a header?
- Was it a big chance?
- Did it occur in open play?
- Was it a set-piece?
The closer to goal a shot, for example, the higher the xG, as you would expect. Headers meanwhile, have a lower xG than shots and so on.