What is xG in football? Expected goals explained for bettors
xG is the number behind almost every serious football prediction. Here is what it measures, why it matters more than the scoreline, and how we use it.
xG stands for expected goals. It measures the quality of the chances a team creates, not just whether they went in.
Every shot gets a value between 0 and 1: how often a shot like that, from that spot and in that situation, is scored. A penalty is worth about 0.76. A header from the edge of the box might be worth 0.03. Add up a team's shots and you get their xG for the match.
Why the scoreline can lie
Football is low scoring, so luck plays a big part in any single result. A team can dominate, create 2.8 xG, hit the post twice and lose 1-0 to one deflected shot.
The scoreline says they lost. xG says they were the better side and will usually win games like that. Over a run of matches, xG is a far better guide to how good a team really is than results alone.
What xG tells you before a match
Two things matter most:
- xG for: how many good chances a team creates. A side averaging 2.0 xG a game is creating a lot.
- xG against: how many good chances it allows. A side conceding 0.8 xG a game is hard to break down.
Put an attack against a defence and you get a reasonable estimate of how many goals each side should score in that match.
How we use it
For every match we estimate expected goals for both teams. We start from how well each side attacks and defends at home and away. Then we adjust for recent form, who is missing through injury, suspension or rotation, and the strength of the opponent.
From those two numbers we work out the chance of every scoreline, 0-0, 1-0, 1-1, 2-1 and so on, and add them up into the chances you see on every match:
- home win, draw and away win
- over and under 2.5 goals
- both teams to score
For example, before Chelsea v Tottenham on 24 October our model had Chelsea at 2.2 expected goals and Tottenham at 1.1. That made Chelsea clear favourites and over 2.5 goals more likely than not.
What xG does not tell you
- Finishing: a team with a great striker can beat its xG for a while, and a team without one can fall short of it.
- Game state: a side 2-0 up often sits deep and gives up chances, so its xG against rises without it being in real danger.
- Small samples: five games of xG can still be noisy. That is why we weight recent games more but never ignore the season as a whole.
The short version
xG measures chance quality. Over time it predicts goals better than goals do. It is the backbone of our model, but not the whole story: team news, form and the betting market all go into every verdict, and every pick goes on our public track record.
Please bet responsibly, and only with money you can afford to lose.
Questions
What does xG mean in football?
xG stands for expected goals: how many goals a team would normally score from the chances it created, based on how often similar chances are scored.
Is a high xG a guarantee of goals?
No. A team can create 2.5 xG and score nothing, or 0.4 xG and score twice. Over many games, though, goals tend to follow xG, which is why it is useful for predictions.
How does Bookie Verdict use xG?
We estimate each side's expected goals for the coming match from their attack and defence at home and away, recent form and team news, then turn those into a chance for every scoreline and result.