The confusing world of the possession stat
Possession isn't as simple as it sounds!
Any football fan will know the possession statistic is one of the favorites amongst commentators and even managers when it suits them. The importance of possession in football differs depending on who you are.
Managers such as Pep Guardiola love to retain possession where as managers such as Jose Mourinho are willing to give up possession if necessary to execute a quick counter-attack.
But depending on where you get your statistics you may notice inconsistencies of up to 5%, this isn’t a mistake they are just simply calculating possession differently. Defined simply as the state of having, owning, or controlling something but when it comes to football possession is anything but simple.
Over the years as football has become stat mad possession a stat that many see to be key to football has proven to be a tricky one, how are you supposed to calculate it?
Statistic site Squawka claims to use the “chess clock” method which calculates possession based on how long each team is in possession of the ball using a timer. Every time a team loses possession of the ball the timer for that team is stopped and the timer for the other team begins.
This method is perhaps what most football fans would understand to be the correct way of calculating possession. However, this method has some issues such as what happens when the ball is out of play? or who is in possession when the ball is in play?
Opta, perhaps one of the biggest football analytic companies, calculated possession simply by using passes until 2017. The method had many flaws such as not accounting for who is in possession of the ball when it was in the air and resulted in them changing their approach.
In 2017 Opta created a new “framework” called a possession. This method counts how many possessions a team has in an entire game and dividing it by the total per game.
Opta defines a possession as starting when a player takes a controlled touch, this does not include headers or tackles and ending when a player no longer has or tries to have control of the ball. This includes interceptions, shots crosses into areas and set pieces.
This data, as well as other statistics, are collected by a 3 man team who are present at every match who use a video-based data collection system to tell every time a player touches a ball and the location of that touch.
Optas method is now the metric used for possession for stat websites such as WhoScored and SofaScore as well as Sky Sports, BBC, and BT Sport and are the Official Premier League website.
So the next time you look up possession statistics and see differences just remember there not necessarily wrong, just calculated differently.