Clásico preview: two ever-closer teams?

Ahead of tonight's clash between probably the two best teams in the world, there are still some issues which are open and up for an educated guess. Besides some personal issues (for instance concerning the state of James or Messi), one of the most interesting questions will be how both teams will start the game in tactical and stylistic terms. Times in which the games between these two clubs were not only battles of club culture and transfer philosophies but also of playing styles are over. Instead, both clubs have come closer in certain aspects, for instance in terms of transfer spending. A closer analysis of some KPI of the last eight liga clásicos shows that this process also takes place in terms of playing style. Meanwhile the games between the clubs when coaches of the likes of Mourinho and Guardiola were in office were marked by a strict antagonism of reactive and rigid, transition-based football applied by Real Madrid and the uncompromising possession football of Guardiola's Barça, changes of managers have led to the evolution of both clubs' playing style away from the ideal points in the continuum between possession- and transition-based football.

In the first four of these eight games, in which Real Madrid were still under the command of José Mourinho, Barcelona clearly dominated possession. They never had less than 60% of it, the values in games against Real Madrid were furthermore only slightly lower than in all the other games. Mourinho did in other words normally not try to obstruct Barcelona's usual style of play but was happy to let them take the initiative, let his own team sit deep and wait for the opponent's errors in order to exploit them rapidly. His team played on average only slightly more than 300 passes in these four games, way below the average value in these two seasons (538 in 2011/12 and 478 in 2012/13, respectively). He adapted his own tactics while not trying to force Barcelona into adapting theirs. At least in these four games, his approach was quite successful; Madrid won two of them and lost only one. Aggregate TSR and STR values of these four games (0.57 and 0.59 in favour of Real Madrid) also show that success in these games was not down to luck, but in general the tactics employed by Mourinho's Madrid were effective in containing Barcelona's attacking power. 

The pattern since then has changed. The number of passes played by Real Madrid in direct duels has risen constantly, meanwhile that of Barcelona declined steadily. In other words, Madrid under Mourinho's successor Ancelotti adapted a more active style in trying to have more of the ball and at the same time destroying Barcelona's game earlier and higher up the pitch. Although they still played less passes against their rivals than against other teams on average with a slightly lower success rate, they also allowed them to play less passes. Graph 1 shows this development, using as indicators the percentage of all passes in the respective game played by Real Madrid and the team's pass success.

Graph 1

Data shows the important differences between Mourinho's and Ancelotti's sides. Meanwhile in the four earlier games Real Madrid played 30 or less percent of all passes in all but one game, they played less than 40% only in one of the latter games. Similarly, passing success was constantly below 80% under Mourinho's mandate but only once while Ancelotti was in office. Again, Madrid also had a higher pass rate under Ancelotti in all other games than under Mourinho, but differences were only minor in those, meanwhile it dropped sharply when facing Barça under Mourinho's reign and much less under Ancelotti's. Interestingly, Ancelotti's approach in games against the rival did not turn out to be as successful as Mourinho's pragmatism. His team won only one game and lost the remaining three, a much worse balance than his predecessor's. Like results, also performance indicators had declined in comparison to the four games under Mourinho (TSR to 0.47 and STR to 0.53).

Pass success rate is among other factors (such as passing skill of the passer, the positioning of his team mates, height and intensity of the opponent's pressing, etc.) strongly dependent on the length of passes played. Simply put, the longer a pass is, the lower the probability it is completed, since the difficulty of placing it correctly increases with distance. The data of graph 1 lets one suppose therefore that Real Madrid also played more short passes in direct confrontations with los culés in the latter games than when Mourinho was in charge. 

Graph 2 confirms this hypothesis. In each of the games under Mourinho, at least one in five passes was longer than 25 yards. In one game, the rate was even below 70%, although in general Mourinho did not take a long ball approach. In all games, the rate of passes shorter than 25 yards was slightly below 90%. This underlines again the altered approach Mourinho usually opted for against Barcelona. In line with the reliance on deep defending and quick counter attacks, his team did not waste a lot of time trying to keep the ball in possession, but rather tried to pass it quickly into more dangerous zones after winning it back in their own half. Under Ancelotti, the rate was below 80% under once and almost reached 90% in his second year. In other words, the style of his team against Barcelona in terms of passing was almost undistinguishable from the one in games against other opposition.

Graph 2

On the other hand, the curve of Barcelona is much smoother than the one of their counterparts. Under Guardiola's successor Tito Vilanova (games 3 and 4), they played even more short passes, while the rate during the respective first game under the following coaches Martino and Enrique. 

Since it is relatively hard to determine whether these statistics are based solely on altered approaches in single games (although it is likely) or down to a more profound evolution of a team's playing style and in order to put them in context, graph 3 shows a comparison of some of the style-relevant indicators over the full seasons. The values were calculated by dividing Real Madrid's average by Barcelona's. Hence, if the value is below one, Barcelona displayed a higher value in comparison to their counterparts and vice versa. 

Graph 3

Indeed, values in 19 out of 20 observations (four KPI in five seasons) are below one, hence Barcelona performed "better" in these terms than Real Madrid. There is however an interesting development going on. Additionally, differences are not equal among KPI. The lines of pass success and the percentage of short passes are relatively constant and not much below one, i.e. the differences between Barcelona and Real Madrid were only minor and did not change a lot during the last four seasons and the current one. The differences in possession and passes per game are much more pronounced and volatile. If we look at the evolution of the differences over time, we observe a trend towards 1 for all indicators. In other words, the teams are becoming more similar in terms of playing style in the long term. The value of each indicator is higher in this season than they were in 2011/12, the last one in which Real Madrid managed to win the league. There was a sharp decline for all indicators in the following season, the last one under Mourinho, and a smaller one between the first and second season under Ancelotti. The long-term development is in any case upward. Under their new manager Benítez, Real Madrid manage for the first time a better pass success rate than their Catalan counterparts, although values for this season are still based on a quite low number of games. The game tonight will show to which dimension the positive trend in this season is down to substantial development.

What can we then take out of these findings and expect for tonight's game? Despite the ongoing trend of harmonization of the teams' playing style, it is still the case that Barcelona tend more towards a possession-based football style. They had more of the ball in all of the last clásicos and will probably do so today as well. In line with last year's games, their amount of possession will however be most likely between 50 and 55% and not above 60. Both teams will play roughly the same percentage of their passes short and have more or the less the same pass success rate. The biggest unknown besides the fitness level of some key players is Rafa Benítez, who will coach in a clásico for the first time and won only four out of his eleven games as a coach against Barcelona. His regularly underlined focus on his teams' balance indicates that he might be more of a pragmatist in the sense of Mourinho than an Ancelotti-like idealist when it comes to facing Barça. In this case, it would not be too surprising if he decided to play Casemiro, benched two of his galactic offensive players (probably Isco and James) and ordered his team to stay deep and narrow, exploiting Cristiano's and Bale's pace in offensive transitions. His team's numbers are however the most similar to Barcelona of any Madrid team of the last years, which is why he might also opt for a more proactive approach tonight. What is clear is that the game will no more represent a clash of football style civilization as it did some seasons ago.

All data extracted from whoscored.com.

Click on graphs to enlarge.