What is xG in football and how to use it in betting

Football is beautiful in its unpredictability. A team can storm the opponent's goal throughout the match, make 20 shots, hit the post twice, but eventually concede a random counterattack and lose 0:1. An ordinary fan would say: "Bad luck". A professional tipster will look at the numbers and see a pattern that can be used for earning. The xG (expected goals) metric helps in this - one of the most useful tools in modern sports analysis. In this article, we will explain what this abbreviation stands for, how expected goals are calculated, and how to turn dry statistics into profitable bets.

What is xG and why is it needed

xG (expected goals) translates as "expected goals". This is a metric that assesses the quality of scoring opportunities created by the team.

Each shot is assigned a danger coefficient - a value from 0 to 1.

0 means that it is physically impossible to score from this situation. 1 is a guaranteed goal (in reality, such a value does not exist, even a penalty is estimated at about 0.76-0.78 xG, as the goalkeeper always has a chance to save).

Why is xG more useful than the regular score?

The scoreboard at the stadium only shows the final result, but often omits the real scenario of the game. The team could win 3:0 thanks to three random long-range shots (the total danger of which barely reached 0.15 xG) and an own goal. At the same time, their opponent missed four one-on-one situations.

The score of the match is 3:0, but the quality of the game suggests that the winner got lucky, and the loser was simply unlucky. xG helps to remove the factor of chance and see the objective picture: who actually dominated on the field, created quality moments, and deserved to win.

How xG is calculated: main factors

At the heart of xG models lies pure mathematics and a colossal array of historical data. Special algorithms analyze tens of thousands of similar shots from the past and determine the probability of a specific attack resulting in a goal.

Many parameters are taken into account when calculating:

• Distance to the goal. The closer the shooter is to the target, the higher the score.
• Angle of shot. A shot aimed at the center of the goal is valued much higher than a shot from a sharp angle.
• Part of the body. A shot with the dominant foot is given more weight than a header or a shot with the non-dominant foot.
• Type of attack. Whether it was a one-on-one situation, a set-piece play, a cross from the flank, or a quick counterattack.
• Position of defenders and goalkeeper. How many opponents were between the shooter and the goal, whether the goalkeeper was able to take the right position.

A simple example for understanding:

• A shot from 40 meters through a wall of defenders. Historically, only 1 out of 100 such balls is scored. The xG value is approximately 0.01.
• A one-on-one situation with the goalkeeper from the center of the penalty area. The forward is unobstructed, the position is perfect. Statistics show that in such situations, goals are scored in 80% of cases. The xG value will be 0.80.

At the end of the match, the indicators of all shots of each team are summed up. This gives us the final xG score of the match — for example, 2.45 against 0.85. It clearly shows by how many goals the opponents outplayed each other.

Practical application of xG for betting

Simply opening a statistics website and betting on the team with a higher xG is a sure way to lose your bankroll. The indicator should be used as a marker of anomalies. Let's provide some effective analysis strategies.

1. Analysis of long-term form (search for undervalued teams)

If a team over the course of 5-6 matches creates chances for 2-3 goals per game (high xG), but scores few or even loses points, bookmakers start to inflate the odds on them. However, math is relentless: if there are chances, goals will come. Betting on the victory or individual total of such an "unlucky" team in the long run will bring profit.

2. Assessment of "luck" (search for overvalued teams)

The opposite situation: a modest club is leading, scoring 2-3 goals in each match with unimpressive play and a modest xG around 0.70. This is called overperformance (excess of goals). Sooner or later, luck will run out, the conversion rate will return to average values, and the team will start losing points. This is a great moment to bet against such a team.

3. Totals predictions

Instead of looking at the average efficiency (which can be distorted by a couple of random routs), add up the xG (created chances) and xGA (allowed chances at their own goal) indicators of both teams. If both sides play open attacking football with high xG values, but bookmakers offer a standard total of 2.5 on an equal line — it's worth considering a bet on the over total.

4. Long-term bets

Midway through the season, the xG table (the so-called "expected points" table — Expected Points, xPTS) often differs significantly from the actual state of affairs. Use this for long-term bets on who will make it to the European cups, maintain their place in thein the league or become the champion. Teams with a good xG structure in the second round usually pick up their points.

xG limitations: when not to rely on the indicator

Despite all its coolness, xG is not a magic wand or a guarantee of victory. This metric has significant limitations that should always be kept in mind.

• Ignoring player skills. The xG model assumes that the shot is taken by an "average footballer". But if Erling Haaland or Kylian Mbappe are shooting at the goal, the likelihood of a goal is always higher than if a defensive destroyer were in their place. The same applies to goalkeepers: a top-level goalkeeper saves "dead" balls much more often than an average goalkeeper.
• Danger without shots. A sharp shot along the empty goal, which the forward missed by a millimeter, is rated at 0 xG. A dangerous three-on-one defender situation, interrupted at the last moment by a precise slide tackle without a shot, is also 0 xG. The metric only sees completed shots, missing the context of potential danger.
• Difference in methods. Each analytical portal has its own algorithms. Understat may show a result of 1.5 xG for a match, while Opta may show 2.1 xG. It is necessary to choose one platform for analysis and stick to its data to avoid confusion with numbers.
• The importance of context. xG does not know about the weather, the quality of the pitch, refereeing mistakes, the atmosphere in the locker room, personnel losses, and motivation. If the favorite doesn't need anything in the tournament plan, its previous high xG numbers will not matter.

The main mistake of beginners: blind faith in numbers over a short distance. You can't draw conclusions from 2-3 matches. xG statistics start to work and reflect the real strength of teams only on a sample of 8-10 matches.