Statistic shows degree of attack threat in the Cup; see Brazil’s performance

Brazil paved the way for a 4-1 victory over South Korea and the consequent qualification to the quarterfinals of the World Cup with an aggressive and efficient possession of the ball in the opening minutes of the duel played this Monday (5).

Metric calculated by Sheet shows that the selection’s actions passed through “threatening” areas of the field in the first moves. The score was opened in the 6th minute, with Vinícius Júnior, and the advantage was extended in the 12th minute, in a penalty conceded by Richarlison and charged by Neymar.

The indicator is known as xT, an abbreviation for the English expression “expected threat”. Basically, it is the probability of a given play ending up inside the net, depending on where it takes place.

Likewise, the goal of honor for the Koreans, 30 minutes into the final stage, also happens at a time when statistics show the greater danger of Asian actions in relation to Brazilian ones. A few minutes earlier, Hwang had already demanded a difficult save from goalkeeper Alisson.

Predictive statistics are more popular every day in football. The best known of these is the xG (“expected goals”, or expected goals), a predicted success rate for each shot depending on where the shot is taken. The calculation takes into account a database with thousands of previous submissions and their respective outcomes.

The problem with xG is that it ignores move building, and many actions in a match do not immediately result in a submission. It’s like analyzing a chess game on the basis of checkmate alone, when the crucial move may have occurred a few turns earlier.

The xT, in turn, assigns a relative danger to each place in the field. The calculation of Sheet considers the probability that, given an action in a given sector of the field, the team manages to reach the goal in the next five plays.

The metric was based on a study published by Arsenal-ING analyst Karun Singh, with data from an entire season of Premier League matches (2017/18). The idea is to attribute credit to moves that put a winger in a crossing situation or break the lines of the marker, among other concrete threats. Singh calculated hazard rates for 196 areas of the field.

In Lucas Paquetá’s goal, for example, Neymar receives a pass from Richarlison in an area with xT equivalent to 3.4%. That is, according to statistics, just over three out of every hundred events in that location end in a goal in up to five subsequent actions.

When playing for Vinícius Júnior on the left end, the number 10 puts the attacker in a point of the field with an expected threat three times greater. After dominating the ball and adjusting his body to cross, Vini already occupies a zone with xT of 12.6%.

To illustrate the moments of each team in the match, the Sheet calculated the moving average of the accumulated xT of each team in a five-minute window, with a greater weight for the most recent one, and so on, until the first minute of the break.