A comprehensive resource for all the official Opta event definitions in football.

Whether you’re an analyst, coach, player, or fan, this guide provides clear and precise explanations of every key football stat tracked by Opta.

Enhance your knowledge, improve your analysis, and enjoy the game with a deeper understanding of its statistics.

Goals and Shots

Goal/Own Goal

Attributing a goal to the goalscoring player, or in the case of an own goal, to the defending player.

Given any contention around assigning a goal to an appropriate player, Opta will apply their own rules, and when applicable will align decisions to the relevant official competition or governing body.   

Shot On Target

A deliberate attempt to score that is on target. Includes all goals being scored and shots on target saved by the goalkeeper.

It also includes shots on target that are blocked by a last-line defending player, preventing the ball from entering the goal.

Shot Off Target

A deliberate attempt to score that misses the target, without contact from a player diverting the ball from on target to off target.

A shot hitting the frame of the goal is classified as a shot off target unless the ball subsequently enters the net. A blocked shot is not classified as a shot off target.

Blocked Shot

A blocked shot is defined as an attempt to score including:

  • An attempt on target that is blocked by an outfield player, where other defenders or a goalkeeper are behind the ‘blocker’.
  • A shot blocked unintentionally by the shooter’s own teammate.

Clearances off the line by an opposition player (last-line blocks) are classified as a shot on target and not as a blocked shot. 

Shot Conversion

A calculation of total goals scored divided by total shots attempted.

Shooting Accuracy

A calculation of total shots on target divided by all shots attempted (excluding blocked shots and own goals).

Big Chances

A situation where a player should reasonably be expected to score, usually in a one-on-one scenario or from very close range when the ball has a clear path to goal and there is low to moderate pressure on the shooter. Penalties are always considered big chances.

Big Chance Missed

A big chance opportunity when the player does not get a shot away, typically given for big chance attempts where the player completely misses the ball (air shot) but can also be given when the player has a big chance opportunity and decides not to shoot, resulting in no attempt occurring in that attack.

Goal/Shot Location

The position of the ball when the shot is taken (shot origin). Any event originating on a line on the pitch will be collected as inside that area. For example, a shot on the 18-yard line will count as being inside the box.

Expected Goals (xG)

Expected goals measures the quality of a chance by calculating the likelihood that it will be scored, using information on similar shots in the past. We use nearly one million shots from Opta’s historical database to measure xG on a scale between zero and one, where zero represents a chance that is impossible to score, and one represents a chance that a player would be expected to score every single time.

Body Part for Goals/Shots

Attributing a goal or shot event to the following four body parts:

  • Right foot.
  • Left foot.
  • Head.
  • Other (between hip and shoulders).

‘Foot’ includes any connection with the leg.

Pattern of Play for Goals/Shots

Set-piece goals/attempts are those where the ball starts from a dead-ball situation such as a corner, a free-kick, a penalty or a throw-in and results in a shot before the phase of play has broken down into open play.

There are seven patterns of play, one of which must be assigned to each attempt.

  • Regular – an attempt created from an open-play attack.
  • Set-piece – an attempt created where the ball starts from an indirect free-kick dead-ball situation.
  • Throw-in – an attempt created from a throw-in.
  • Direct free-kick – an attempt at goal directly from free-kick situation.
  • Direct corner – a goal scored directly from a corner by the corner-taker, or an attempt created from a corner situation.
  • Fast break – an attempt created after a team quickly turn defence into attack, winning the ball in their own half (counter-attack).
  • Penalty – The penalty attempt itself, any follow-up shot would be classed as a set-piece attempt. Passed penalties are also counted as ‘penalty’ pattern of play.

The relevant pattern of play is assigned to a shot before the phase of play has broken down into open play.

The exact point at which it becomes open play is usually clear, but set-pieces and corners that are cleared and then the ball is put straight back into the penalty area are still deemed to be part of the set play as the defending team is still positioned to deal with the set play. This rule includes free-kicks, corners, throw-ins and penalties.

Passing

Goal Assist

The final touch from a teammate that leads to the recipient of the ball scoring a goal. If the assist is deflected by an opposition player, it must be deemed as travelling to the goalscorer irrespective of the deflection. 

In the event of an own goal, direct free-kick goal and direct corner goal, an assist will not be awarded. This same rule applies to penalties unless the penalty-taker chooses to pass the ball for another player to score. Also see ‘fantasy assist.’ 

Fantasy Assist

Attributing a collection of assist events outside the conventional categorisation of goal assist. Classifies the final touch from a player on the scoring team as a fantasy assist, despite:

  • A heavily deflected pass or cross.
  • Shot on target saved and rebound scored.
  • Blocked shot and rebound scored.
  • Shot hit woodwork and rebound scored.
  • Shot off target, remains in play and rebound scored.
  • Penalty won.
  • Free-kick won by foul.
  • Free-kick or penalty won from a handball.
  • Event preceding an own goal (usually shot/pass/cross).

Second Assist

A pass/cross that is instrumental in creating a goalscoring opportunity; for example, a corner or free-kick to a player who then assists an attempt, a chance-creating through ball or cross into a dangerous position.

Key Pass

The final pass from a player to their teammate who then attempts a shot on goal without scoring.

Chance Created

A cumulative total of ‘assists’ and ‘key passes’.

Pass

The attempted delivery of the ball from one player to another player on the same team. A player can use any part of their body (permitted in the laws of the game) to execute a pass. Event categorisation includes open-play passes, goal-kicks, corners and free-kicks played as a pass. Crosses, keeper throws, and throw-ins do not count as a pass. Opta adds a whole range of qualifiers to each pass event so that various things can be measured.

  • Chipped pass – A lofted ball with an intended recipient. Must be over shoulder height and using the pass’s height to avoid opposition players.
  • Headed pass – A header when there is an intended recipient.
  • Launch – A long high ball into space or an area for players to chase or challenge for the ball.
  • Flick-on – A glancing pass with head or foot to a teammate when the ball is helped on in the same general direction.
  • Pull-back – A pass attempted where a player in the opposition’s penalty box reaches the by-line and passes (cuts) the ball backwards to a teammate. Crosses are excluded.
  • Lay-off – A first-time pass away from goal when there is pressure on the passer (typically a forward) with one touch when they have their back to goal.
  • Through ball – A pass splitting the defence for a teammate to run on to.
  • Tap pass – A short pass after a dead-ball situation that cannot have an unsuccessful outcome, such as rolling the ball a very short distance from a free-kick to a teammate to shoot.

Each pass is logged with X and Y coordinates for its points of origin and destination.

This allows Opta to log the following:

  • Passes broken down by area of the pitch, for example own half/opposition half or defensive/middle/final third or left/right/centre.
  • Passes broken down by type, for example short/long, short medium/long.
  • Pass direction, for example backwards/sideways/forwards.

In summary, the event-based nature of the data is such that you can calculate any combination. For example, a chipped pass over 20 yards in the final third that goes sideways.

Pass Completion

This is simply a formula where successful passes are divided by total attempted passes in whichever combination of passes is selected. Usually, pass completion excludes crosses.
Crosses are usually treated separately and crossing success is the percentage of successful crosses out of the total attempted.

A completed pass is a pass that goes to a teammate directly without a touch from an opposition player.

Progressive Pass

A completed pass in the attacking two-thirds of the pitch that moves the ball at least 25% closer to the goal.

Cross

A ball played from a wide position that targets a teammate(s) in a central area in close proximity to the goal. The delivery must have an element of lateral movement from a wider position to a more central area in front of goal. 

Expected Assists (xA)

Expected assists measures the likelihood that a completed pass will become a goal assist. It considers several factors including the type of pass, end-point and length of pass. Adding up a player or team’s expected assists gives us an indication of how many assists a player or team should have based on their build-up and attacking play.

Sequences

Sequences are defined as passages of play that belong to one team and are ended by a defensive action, a stoppage in play or a shot.

  • Sequence time: The time in seconds of a sequence.
  • Passes: The number of passes in a sequence.
  • Progress: The distance (in metres) that the ball moves towards opponent’s goal-line during the sequence.
  • Length: The total distance (in metres) that the ball travelled during the sequence.
  • Speed: Length divided by sequence time (average speed of ball movement during sequence).
  • Direct Speed: Progress divided by sequence time (average speed of ball movement towards opponent goal line during sequence).
  • Width: The distance (in metres) between left-most point in a sequence and right-most point in sequence.
  • Absolute Width: The furthest distance (in metres) the ball is away from the centre of the pitch in a sequence.
  • Involvement: The number of sequences that a player was involved in. Involvement is defined as a player having at least one touch in the sequence.

Open-Play Sequence Involvement

The number of unique open-play sequences that a player was involved in.

(Note: these are unique because multiple involvements in a single sequence will only count as one involvement)

Shot-Ending Sequence Involvement

The number of unique shot-ending sequences in open play that a player is involved in.

Possessions

Possessions are defined as one or more sequences in a row belonging to the same team. A possession is ended by the opposition gaining control of the ball.

Build-up Attacks

The number of open-play sequences that contain 10+ passes and either end in a shot or have at least one touch in the opposition’s box.

Direct Attacks

The number of open-play sequences that start just inside the team’s own half and have at least 50% of movement towards the opposition’s goal and ends in a shot or a touch in the opposition’s box.

Touches

Touches

A sum of all collected events where a player touches the ball, so this excludes events such as aerial lost or challenge lost.

Touch/Unsuccessful Touch

When the ball bounces off a player and there is no intentional pass, we award a touch. When a player mis-controls the ball with a poor touch, we award an unsuccessful touch. Also used for mishit shots that go backwards towards a player’s own goal.

Dribble/Take-on

This is an attempt by a player to beat an opponent when they have possession of the ball. A successful dribble means the player beats the defender while retaining possession, unsuccessful ones are where the dribbler is tackled. Opta also collects attempted dribbles where the player overruns the ball with a heavy touch when trying to beat an opposition player.

Total take-ons includes all take-on events, while total dribbles is all take-on events without the ‘defensive 1-vs-1’ qualifier. This qualifier is meant to signal when a player attempts a take-on but doesn’t get past a player and basically has to turn back (still with the ball). Any take-on with the ‘defensive 1-vs-1’ qualifier is unsuccessful so this doesn’t affect the number of successful take-ons/dribbles.

Tackle

A tackle is defined when a player connects with the ball in a legal, ground-level challenge and successfully takes the ball away from the opposition player. The tackled player must be in controlled possession of the ball to be tackled by an opposition player.

  • A tackle won is deemed to be when the tackler or one of their teammates regains possession because of the challenge, or when the ball goes out of play and is safe.
  • A tackle lost is when a tackle is made but the ball goes to an opposition player.

Both are categorised as tackles, but the outcome of the tackle (won or lost) is different based on where the ball goes after the tackle.

Missed Tackle

This is where a player attempts to challenge for the ball and does not make it – it is calculated by adding fouls with an attempted tackle qualifier to the number of times a player is beaten by a dribble (challenge lost).

Interception

This is where a player reads an opponent’s pass and intercepts the ball by moving into the line of the intended pass.

Block

When an outfield player blocks an attempt on goal from an opposition player. If the attempt is going wide of the goal, then no block is awarded. 

Blocked Pass

When a player tries to cut out an opposition pass by any means. Similar to an interception except there is less reading of the pass.

Clearance

A defensive action when a player attempts to get the ball away from a dangerous zone on the pitch with no immediate target regarding a recipient for the ball. 

High Turnovers

The number of possessions that start in open play and begin 40 metres or less from the opponent’s goal.

High Turnovers Ending in a Goal/Shot

The number of shot-ending or goal-ending sequences that begin with a high turnover (where a high turnover is a possession that started in open play and begins 40 metres or less from the opponent’s goal).

Pressed Sequences

The number of open-play sequences starting in their defensive third where the opposition has three or fewer passes, and the sequence ends in their own half.

Start Distance

The average distance (in metres) from their own goal that a team starts their open-play sequences.

PPDA – Passes Allowed per Defensive Action

PPDA is the number of opposition passes allowed outside of the pressing team’s own defensive third, divided by the number of defensive actions by the pressing team outside of their own defensive third. 

In our PPDA calculation, the defensive actions are fouls, tackles, interceptions, challenges, and blocked passes.

Ball Carries

Carry

Defined as the player moving the ball five metres or more.

Carry Distance

The distance (in metres) of a player’s ball carry/carries.

Progressive Carries

Ball carries that move the ball more than five metres upfield.

Goal/Shot-Ending Carries

Carries that result in a shot (including goals) or in a goal.

Assist/Chance Created Ending Carries

Carries that result in a chance being created or directly as a goal assist.

Carry Directness

The percentage of the total distance covered per ball carry that is upfield distance (carry directness = total progressive carry distance/total carry distance).

Duels

Duel

A duel is a 50-50 contest between two players of opposing sides in the match. For every duel won there is a corresponding duel lost depending on the outcome of the contest.

Aerial Duel Won/Lost

This is where two players challenge in the air against each other. The player that wins the ball is deemed to have won the duel. When more than two players are involved the player closest to the duel winner is given an aerial duel lost.

Tackle – Unsuccessful Take-on/Dispossessed

A tackle is awarded if a player wins the ball from another player who is in possession. If they are attempting to beat the tackler, the other player will get an unsuccessful take-on. If they are in possession but not attempting to ‘beat’ their opponent, then they will get a ‘dispossessed’.

Successful Take-on – Challenge Lost

The player who has been beaten is given a challenge lost if they do not win the ball.

Foul Won/Conceded

The player winning the foul is deemed to have won the duel and the player committing the foul is deemed to have lost the duel. Collection of the two foul events is subject to the referee awarding a free-kick or penalty and not the taking of either.

Smother – Unsuccessful Take-on

A goalkeeper who comes out and claims the ball at the feet of a forward gets a smother – similar to a tackle, however, the keeper must hold on to the ball to be awarded a smother.

Other Categories

Recovery

This is where a player recovers the ball in a situation where neither team has possession or where the ball has been played directly to him by an opponent, thus securing possession for their team.

Hit Woodwork

When the ball hits any part of the goal frame but does not enter the net as a direct consequence.

Any single attempt hitting the goal frame multiple times (bar then post, for example), will only count as hitting the woodwork once. ‘Hit woodwork’ is only collected for the attacking team and can be attributed to any player on the pitch.

Error Leading to Goal/Shot

When a player makes an error, which leads to a goal or shot conceded. Also used for spills and attempted claims or saves by a goalkeeper that directly lead to a second attempt to score.

Foul Conceded

A ‘foul conceded’ is defined as any infringement penalised as foul play by the referee and results in a free-kick or penalty event.

  • Offsides are not given as a foul conceded.
  • Incidents where a match official has played advantage and subsequently cautioned a player do not contribute towards the total foul count for the player or team.

In these scenarios a free-kick or penalty event must occur for a foul to be awarded. 

Foul Won

A ‘foul won’ is defined as when a player wins a free-kick or penalty for their team after being fouled by an opposing player.

There are no fouls won for a handball, dive, back pass, illegal restart, dissent, goalkeeper six-second violation or obstruction where a free-kick is conceded. Those events are defined as followed:

  • Handball – A deliberate handball by an opposition player.
  • Dive – A deliberate attempt for an opposition player to deceive the referee and win a free-kick.
  • Back Pass – A pass picked up by a goalkeeper when played by a teammate.
  • Illegal Restart – A player has consecutive touches directly after a dead-ball situation.
  • Dissent – A player shows dissent towards a match official.
  • Goalkeeper six-second violation – A goalkeeper picks up the ball and holds on to it longer than six seconds.
  • Obstruction – A player traps the ball between their legs to stop an opposition player from playing the ball.

Penalty – Won/Conceded/Taken

Attributing a series of sequential penalty events to the appropriate team and player.

Collection comprising; ‘penalty won’, ‘penalty conceded’ and ‘penalty taken’.

Offside

An event attributed to the player deemed to be in an offside position when a free-kick is awarded.

If two or more players are in an offside position when the ball is played, the player considered to be most actively involved is given offside. An offside provoked will be awarded to the deepest player in the defensive line when an offside has been given.

Corner – Won/Lost/Taken

When the ball has left the field of play for a corner.

A ‘corner won’ is collected for the team awarded the corner, and ‘corner lost’ to the team conceding the corner. A ‘corner taken’ is recorded when the attacking team have (or attempted to), return the ball back into play from a corner event. 

Due to the difference in collection criteria between corner won/lost and corner taken, it is possible their respective aggregate totals could differ.

Cards

Cards are collected as yellow, second yellow or red card. Where possible, Opta cross-check cards against official (referee) reports to match the official statistics – unless these are clearly incorrect.

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