What is xG (Expected Goals)?
A complete guide to understanding Expected Goals and how it revolutionizes football analysis
Expected Goals (xG) is one of the most important metrics in modern football analytics. It measures the quality of a shot by calculating the probability that it will result in a goal.
Unlike traditional statistics that simply count goals, xG provides context about how likely a shot was to score based on historical data. This helps identify whether a player or team is performing above or below their expected level.
xG models use machine learning algorithms trained on thousands of historical shots. Each shot is assigned a value between 0.0 (impossible to score) and 1.0 (certain goal) based on multiple factors:
📏 Distance to Goal
Shots taken closer to goal have higher xG values. A shot from 6 yards has much higher xG than one from 30 yards.
📐 Angle to Goal
Shots taken from a central position have higher xG than those from tight angles or wide positions.
👟 Body Part Used
Shots with the foot typically have higher xG than headers, which are generally more difficult to control.
⚡ Type of Assist
Through balls and cutbacks typically lead to higher xG chances than crosses or long balls.
🛡️ Defensive Pressure
Number of defenders between the shooter and goal affects the likelihood of scoring.
⏱️ Game Situation
Whether it's open play, a set piece, counter-attack, or penalty affects xG calculations.
📌 Example:
A shot from 12 yards out, central position, with the right foot, after a through ball, with only the goalkeeper to beat might have an xG of 0.45 – meaning there's a 45% chance it results in a goal based on historical similar shots.
🎯 Measures True Performance
Goals can be affected by luck, but xG shows the quality of chances created and conceded. A team might win 1-0 but have an xG of 0.3 vs 2.1, indicating they were outplayed.
🔮 Predicts Future Performance
Over the long term, xG is a better predictor of future results than actual goals. Teams that consistently outperform their xG (score more goals than expected) usually regress to the mean.
⭐ Identifies Player Quality
Comparing a player's actual goals to their xG reveals their finishing ability. Consistently scoring above xG indicates elite finishing. Creating high xG shows playmaking ability.
💰 Informs Transfer Decisions
Clubs use xG to identify undervalued players who create high-quality chances but may have been unlucky with finishing, or to avoid overvaluing players on unsustainable hot streaks.
On Mercato XI, you can view xG data for players across different competitions and seasons:
- Player Pages – View total xG, xG per 90, and xG per shot
- Shot Maps – See the location and xG value of every shot
- Season Comparisons – Track xG performance across multiple seasons
- Goals vs xG – Identify overperformers and underperformers
What is xG in football?
xG (Expected Goals) is a metric that measures the quality of a shot based on several factors such as distance to goal, angle, type of assist, and body part used. It assigns a value between 0 and 1 to each shot, representing the probability of it resulting in a goal.
How is xG calculated?
xG is calculated using statistical models that analyze thousands of historical shots. Factors include: distance from goal, angle to goal, type of assist (through ball, cross, etc.), body part used (foot, head), defensive pressure, and game situation.
Why is xG important?
xG helps identify which teams and players are creating high-quality chances versus getting lucky or unlucky with finishing. It provides context beyond simple goal tallies and can predict future performance better than goals alone.
What is a good xG value?
For individual shots, anything above 0.3 xG is considered a good chance. For players over a season, top strikers typically achieve 0.5-0.8 xG per 90 minutes. Total team xG above 2.0 per match indicates strong attacking play.
What does xG per 90 mean?
xG per 90 (or xG/90) normalizes expected goals to a 90-minute match. It shows how many expected goals a player generates per full game, making it easier to compare players with different playing times.