Move over, xG! LaLiga’s new ‘Goal Probability’ metric sheds new light on classic goals from Cristiano Ronaldo, Lionel Messi and more

Expected goals (xG) has become the standard method to measure the quality of a shot at goal by calculating the likelihood of it hitting the back of the net. The advanced metric has been embraced by some fans, and left others non-plussed at reading that their team had an xG, for instance, of 0.93 after a match. But now, LaLiga has developed its own “Goal Probability” metric that shows visually the percentage chance of a goal being scored by any player at any given moment during any match in the Spanish top flight, and it has been applied to some of the most amazing goals ever seen in the history of the league from the likes of former Real Madrid great Cristiano Ronaldo and ex-Barcelona icon Lionel Messi.

LaLiga’s new metric takes into account the attacking and defending players’ positions on the pitch among nine variables to calculate the probability of the shooter being able to convert the chance as a percentage rating between 0-100%.

The attacker’s distance from goal, proximity to defenders, the positioning of the goalkeeper, and the shooter’s ability are all factors, as is the nature of the chance in question — be it a one-vs.-one, a simple tap-in, or even a thunderbolt volley from 30 yards.

The Goal Probability metric was established using a process that involved trawling through over 2,000 LaLiga matches to review and analyse more than 20,000 shots on goal in order to crunch the data and produce a viable mathematical model.

In simple terms, a world-class striker with the ball at their…