THERE are many broad footballing styles. “Long-ball”—in which the midfield is bypassed as defenders shunt the ball towards a muscular striker—is particularly associated with some English sides. “Catenaccio”, whereby a team relies on a strong defence to absorb pressure before launching a counter-attack, is a label often applied to Italians. The “pressing game”, which requires teams to harry opponents high up the field, now seems to be the tactic de jour throughout much of Europe.

But few individual teams can boast a style of play so distinct that a term must be coined to describe it and it only. The Tottenham Hotspur side which won the English league in 1950-51 is alone in being described as the team of “push and run”. Talk about “total football” and everyone will know you are referring to the Ajax side that dominated Europe in the early 1970s (or, perhaps, the Dutch national side of that era which included many players brought through the Ajax team). And, in the modern game, there is Barcelona and “tiki taka”.

Defining a unique football style can be like defining obscenity—you know it when you see it. But it is difficult to quantify exactly how different a team such as Barcelona is compared with its peers. Goals are the currency of football, but they tell us little about teams’ modi operandi. People might come up with a broad shorthand—that, in the case of tiki taka for example, maintaining possession of the ball is the defining characteristic. This is certainly true: Barcelona went an incredible 317 consecutive games in which they had more than 50% possession. However, they aren't unique in trying to accomplish this, they are merely better at it.

So is it possible to define tiki taka through statistics? Laszlo Gyarmati of the Qatar Computing Research Institute and two colleagues have made a promising start. The group conducted an analysis of the passing patterns of every team in Europe’s five biggest leagues—England, Spain, Germany, France and Italy—during the 2012-13 season. One of their tools was principal component analysis, a technique which measures the relative influence of factors within a set of data, rather than just plotting those data on standard axes. The resulting paper was presented at the KDD Workshop on Large-Scale Sports Analytics. In a three-pass sequence there are five possible combinations. When he receives a pass, a player can either return the ball whence it came or move it to a different member of his side. That player can then pass it back to either of the two people who have already been involved in the move or to someone new. These strings of passes can be represented as: ABAB, ABAC, ABCA, ABCB and ABCD. For longer periods of possession, component three-pass sequences were analysed (in a four-pass move, for example, there are two separate strings of three passes). As the chart above shows, when viewed in this way, all teams across Europe's five big leagues cluster around a remarkably similar style; differences between them can be plotted, but there are no outliers. Except one. Of the 98 sides (and over 1m passes) that were studied, Barcelona, the researchers found, really do have a style all of their own. They are characterised by a much greater propensity to play ABAC and ABCB passing sequences, as well as ABAB (a trait they share with more teams). In other words, having passed the ball, a player is very likely to receive it back straight away. Man on!

This puts the onus on the player passing the ball, who is likely to have an opponent challenging him, then to move quickly so as to take the return. Logic also strongly suggests it means prioritising possession over a quick, forward progression, as the action occurs across a smaller area (although this is not explicitly proved by the study).

Dr Gyarmati foresees powerful practical applications for this method. The most promising area is probably player recruitment. Armed with a quantitative measure of playing style, teams could break down how well potential acqusitions are likely to fit in. That would enable them to identify players who would be particularly well-suited to join their existing roster, and thus likely to make a contribution in excess of their pay cheques.

It also suggests, at least in this instance, that being an outlier works. The Barcelona side of tiki taka was the most successful of its age, winning three Champions League titles since 2006 and Spain's La Liga four times in five seasons. But in the past couple of years, the pack has begun to catch up. Indeed, Bayern Munich, the side that many now consider the most likely to take Barcelona's mantle, play in a way clearly influenced by tiki taka—not least because they poached the Barcelona manager most associated with the style, Pep Guardiola. Just as in business, the only thing harder than coming up with a breakthrough innovation is keeping it out of the hands of the competition.

(Photo credit: JOSE JORDAN / AFP)