Take the ball, pass the ball — a simple method for analyzing passing behaviour FS Follow Apr 8 · 5 min read

Years ago, we only looked at pass completion rates of teams or players as a statistic. Recently, many statistic sites also report the amount of progressive passes. However, the definition of progression is often unclear or it includes only the x-axis, i.e. the length of the pitch.

In this post, we want to show how passing data can answer interesting tactical questions. It also proposes a simple measure for the value of a pass — namely by the distance to goal of its destination. This is also in line with most of the expected goals models.

Distance to opposition goal

I want to point out that there are many research papers on that topic which are far more general, e.g. by including other event types or sequences of passes. For example, see the paper below or references therein.

However, as we will see in the following, our simple approach still opens up many interesting ways of analyzing passing data.

We start with splitting the football pitch into equally sized rectangles, which are called zones from now on (as in the picture above). For each pass, we know its start and end point as well as if it was succesfull. Hence, for each pair of zones i and j we can count all passes that went from i to j. This gives a matrix of pass counts.

From there on, many analyses can be carried out: we can for example look at the probability for a pass attempt (or a succesfull pass) to zone j, given that the player in possession is currently in zone i. Similarly, we can also look at the probability for a pass to originate from zone j, given that it landed in zone i. These can be aggregated on player or team level.

What is this good for?

Only by looking at the distribution of passing destinations/origins, some interesting questions for coaches or scouts could be answered:

Which zones are targeted from a team in a certain phase of buildup or attacking play? On the other side, does a team have a weak spot, i.e. a dangerous zones where it concedes (above average) many passes. On a player level, which are the favourite target zones of a player? Which zones does he pass very seldomly, maybe because of worse perception capabilities? Are the success rates of players evenly distributed or does he have a weak side. If we give a value to the zones (which we will do in a second), is a player rather risk-averse in his passing or not? Only looking at passing rates may be misleading in that aspect.

An FC Barcelona showcase

To make this a more practical, I used (again) the Statsbomb Messi dataset for analyses of the FC Barcelona passing behaviour.

Looking at Barcelona as a team, we can clearly see how their passing behaviour evolved over the years: in the last seasons, the volume of passes — especially high up the pitch — decreased. The clear (horizontal) structure — wings, halfspaces and the center lane — from the years under Guardiola and Luis Enrique slowly faded out into a more uniform distribution.