Performance Indicators in Football

Micheal Hughes et al discussed in 2012 in their article "Moneyball and soccer - an analysis of the key performance indicators of elite male soccer players by position", how team sports like football offer an ideal scope for analysis thanks to the numerous factors and combinations, from individual to teams, that can be used to identify performance influencers.

READ HUGHES M.D. ET AL'S FULL ARTICLE HERE

The article suggests that, in a sport like football, in order for a team to be successful, each player must effectively undertake a specific role and a set of functions based on the position the play in on the field. Through a study carried out with 12 experts and 51 sport science students, they aimed to identify which are the most common performance indicators that should be evaluated in a player's performance based on their playing profile. They started by defining the following playing positions in football:

  • Goalkeeper
  • Full Back
  • Centre Back
  • Holding Midfilder
  • Attacking Midfilder
  • Wide Midfielder
  • Strikers

Each performance indicator identified by position would be then categorized into the following 5 categories:

  • Physiological
  • Tactical
  • Technical - Defensive
  • Technical - Attacking
  • Psychological

Through group discussions between the experts and the level 3 sport scientist, they came up with the following traits required for each of the above positions.

Source: Moneyball and soccer by Michael Hughes et al (2012)

Source: Moneyball and soccer by Michael Hughes et al (2012)

The study identified that most performance indicators of outfield players were the same across position, with only the order of priority of each PI varying by position. Only goalkeepers had a different set of PIs than any other position. While these classifications of skills by position were done in a subjective method (ie. group discussion), it is a good first step towards the creation of techno-tactical profiles based on the players position and functions on the field, as pointed out by Dufour in 1993 in his book 'Computer-assisted scouting in soccer'. The above table provides a framework in which coaches and analyst can further evaluate the performance of players in relation to their position. However, tactics and coaching styles or preferences may cause the order of priority of each PI within each category to vary by team. The article also suggests that a qualitative way of measuring the level of each performance indicator should be used to evaluate a particular player.

The above suggests that positions may play a key role when assessing performance in footbal. From a quantitative perspective, when analysing the performance indicators to determine success or failure, or even to establish a benchmark to which to aim for, there are several metrics an analyst will look to gather through notational analysis:

Technical:

  • Shooting game
    • Total number of goals
    • Total number of shots
    • Total number of shots on target
    • Total shot to goal scoring rate (%)
    • Total shot on target to goal scoring rate (%)
    • Shots to goal ratio
    • Shots on target to goal ratio
    • Total number of shots by shooting position (ie. inside the box)
    • Total number of shots by shot type (ie. header, set piece, right foot, etc.)
    • xG (read more)
  • Passing game
    • Total number of passes
    • Total pass completion rate (%)
    • Total number of short passes (under X metres away)
    • Total short pass completion rate (%)
    • Total number of long passes (over X metres away)
    • Total long pass completion rate (%)
    • Total number of passes above the ground
    • Total chip/cross pass completion rate (%)
    • Total number of passes into a particular zone (ie. 6 yard box)
    • Total zone pass completion rate (%)
    • Pass to Goal ratio
    • Total number of unsuccessful passes leading to turnovers (ie. interceptions)
    • Total pass turnover rate (%)
  • Defensive game
    • Total number tackles
    • Total number of tackles won
    • Total tackle success rate (%)
    • Total number of tackles in the defensive third zone
    • Total number of tackles won in the defensive third zone
    • Total number of fouls conceded
    • Total number of fouls conceded leading to goals conceded (after X minutes of play without possession)
    • Total number of pass interceptions won
    • Total number of possession turnovers won

Tactical:

  • Attacking
    • Total number of set pieces
    • Total number of attacking corners
    • Total number of free-kicks (on the attacking third zone)
    • Total number of counterattacks (ie. based on X number of passes between possession start in own half to shot)
    • Average duration of attacking play (from possession start to shot)
    • Average number of passes per goal
  • Possession
    • Total percentage of match possession (%)
    • Total percentage of match possession in opposition's half
    • Total percentage of match possession in own half
    • Total number of possessions
    • Total number of non-shooting turnovers
    • Ratio of possessions to goals
    • Total number of passes per possession
    • Total number of long passes per possession
    • Total number of short passes per possession
  • Defensive
    • Total number of clearances
    • Total number of offsides by opponent team
    • Total number of corners conceded
    • Total number of shots conceded
    • Total number of opposition's passes in defensive third zone
    • Total number of opposition's possessions entering the defensive third zone
    • Average duration of opposition's possession

It is important to note that teams may adapt both their tactics and style of play based of the various circumstances they face in a game. For example, a team scoring a winning goal in the last 10 minutes may chose to give up possession in order to sit back in their defensive third during the remaining of the game. When using quantitative analysis to determine the success or failure again the performance indicator, it is important to take context into consideration for a more complete and accurate analysis.