Since we launched Squawka in June 2012 we've had quite a few questions about some of the football stats on the site. What is a key pass? What is a take-on? What on earth is an aerial duel?? With those and many other questions in mind we decided to let data analyst Dave O'Brien give us some definitions of some of the basic (and more complicated) metrics that we display on the site. If you think of anything else that needs added to this page then email us [email protected] Squawka calculates the following statistics from a raw feed licensed from our data provider Opta. Here is a brief summary of the statistics we count and calculate across the site.
Contrary to a lot of sites, we calculate possession by working out how long each team has the ball in possession. We start our timer on the first of two consecutive passes, a keeper picking-up the ball or a keeper smothering the ball. The timer runs for the duration of successful passing events in the string. The string is ended if the ball goes out of play or possession is lost. This is then totalled and the respective percentage is calculated for each team. The total possession percentage is worked out by summing the total minutes in possession of both teams, then dividing the total minutes in position of each team by total possession minutes.
Squawka counts the following as Passes and therefore includes the events it in it's calculation of Pass Accuracy:
- Key Passes & Assists
- Headed Passes
- Through Balls
- Long balls (over 35 yards)
- Ground passes
We don't count the following as Passes and therefore don't include the events in our calculation of Pass Accuracy:
- Keeper Throws
- Goal Kicks
N.B. Crosses and Corners are counted separately and Goalkeepers have their own separate distribution statistics. Also, Key Passes & Assists that are subsidiaries of the above are not included in our calculation of Pass Accuracy.
Miss – Any shot on the goal which goes wide or over the goal. Saved – A shot saved by the goalkeeper. Blocked – A shot blocked by an opposing player. Woodwork – A shot that hits either post or the bar.
Chance created – A pass that leads to a shot on goal. Keypass – A pass that leads to a shot on goal that is not converted. Assist – A pass that leads directly to a goal.
A failed tackle – A tackle that hasn’t won possession, could be a foul. Take on – Attempted dribble past an opponent. Aerial – Aerial duel 50/50 when ball is in the air. A lost aerial duel – An aerial duel that has been lost, could be a foul.
Interception – When a player cuts out an opposition pass. Block – A shot is
Clearance – Player under pressure clears ball from defensive zone.
Action Heat map – displays the areas of the pitch where on-ball events most frequently happen. Action Areas – Highlights where on-ball events happen on the pitch according to Squawka’s 13 action areas.
Squawka licenses all of the football data you see on it's products from Opta. Opta collect 99% of its data live and checks all key events (shot, goal, assist) immediately post match. They then perform a full quality control using a different team of analysts within 24 hours. You can find more information about Opta's data feeds here.