Juventus has played nine Serie A game, about one-fifth of the season. They have won seven games and lost twice, allowing them to sit on top of the league table with 21 points. Their end result is certainly better compared to last season when they only had 12 points after nine rounds and sat at 12th in the league. But how well —or not well —do they perform this season?
Here I use some of the available data to analyze Juventus' individual player and team performance. By comparing this year's and last year's data, there are some surprising findings regarding how the team and individual players perform this year.
One should bear in mind that these data only provide a general picture of different players play. They may not be precise enough to describe the particular context each player faces. Moreover, the differences found from various comparisons only represent a trend. The availability of the data does not allow for proper statistical analysis. I also only look at the data from Week 1 to Week 8, therefore this does not include the loss to AC Milan from this past weekend.
The general picture
This year Juventus performs very similarly to last season both in offense and defense. They score and concede almost the same number of goals per match. They have nearly the same amount of possession and pass success rate. However, some offensive and defensive details differ between this and last year. For example, this year Juventus creates more shots per match. Because they only score a similar number of goal as last year, it suggests that this year Juventus is worse in finishing chances.
Another difference comes from defense. Juventus only conceded about 8.9 shots a game last year and was the fewest in Serie A. (Napoli was second with nine shots a game.) This year Juventus improves, even more, only concede 6.7 shots a game. Again it is the fewest in Serie A (Genoa is second with 8.9 shots conceded a game.) This is a massive improvement.
Moreover, Juventus also changes the way they distribute the attack this year. Last season they attacked equally between the left- and the right-hand side. However, this year Juventus spends a lot more time attacking the right-hand side.
I will use data from individual players to try to determine what causes these differences.
Here l look at the number of passes placed by an individual player per minute they are on the field. I made the assumption that the number of passes played by each player reflects the amount of time they spend in the area he occupies (this is the only data that is available for this purpose). If we only focus on the players who play wingback, it is evident that this year Dani Alves has a very high number of passes per minute. In fact, he has more than 0.87 passes per minute, a number that is only surpassed by Andre Pirlo in 2014-2015 (who had 0.9 passes per minute) in the last three years. Being the first choice right wingback this year, he is bringing about 40 more passes each game compared to Stephan Lichtsteiner, a number that is enough to cause the 10 percent difference between the left- and right-hand side attack distribution. It is surprising how his ball loving style can cause such a massive change of the team's attack pattern.
Who is Juve’s best defender?
It is widely accepted that Juventus has one of the best defense — if not the best — in the world at the club level. They have one of the best keepers in the history in Gigi Buffon. Andrea Barzagli, Leonardo Bonucci and Giorgio Chiellini form the great BBC backline in front of him. Talented youngster Daniele Rugani has been a reliable backup for any of them. They are flanked by Patrice Evra, Alex Sandro and Stephan Lichtsteiner. This year also sees Dani Alves and Medhi Benatia joining this great defense.
One question is: Who is the best performer among all defenders during the defensive phase? Also, how do the newcomers perform when comparing to the old guards?
Here I look at two sets of data. I do not include Evra's data this year because he has only played in very few league games. The first one is the total number of tackles a player makes per minute. Another one is the tackle success percentage: For every tackle a player made, how many of them are successful (instead of being dribbled past). One equals to 100 percent, meaning that all of the tackles are successful. In fact, Benatia ranks in the top 6 in both categories among all central defenders have played more than one game in Serie A. You almost can never dribble past Benatia when he is tackling you.
Not only does Benatia outperform his teammates regarding tackles, but he also has the highest number of interceptions and clearances per minute. Using all of these data to measure the defensive performance of a player, one will argue that Benatia is our best defender right now.
Another surprising finding is that Lichtsteiner performs very badly among all of these measurements. He ranks last in every category. And it is not due to his role as a wing back, because Evra, Alex Sandro, and Dani Alves perform very similarly to the central defenders in most categories. In fact, Lichtsteiner ranks last in every category this and last year among all Juventus’ defenders. These data argue that, defensively, he may not be as solid as his teammates.
One should beware that Juventus plays a position-oriented zonal-marking system. Instead of trying to attack the ball or the ball handler, Juventus' defenders prioritize marking the zone/space. The defense is passive. A major goal is to force the opponent to make mistakes. And, therefore, some of the merits might not be reflected by these data. Nevertheless, these data still suggest that Benatia and Dani Alves strengthen and complement Juventus' defense.
Who is the best replacement for Marchisio?
Since Pirlo left, Claudio Marchisio is arguably most important Juventus's midfielder. Since his injury, Massimiliano Allegri has used Mario Lemina, Miralem Pjanic, and Hernanes as the central defensive midfielder. How does each of them perform in this role?
I compare the data of several attributes that are important as a central defensive midfielder. All of the data are normalized with the same measurement of Marchisio in 2015-2016. A number of one would mean that is the same as Marchisio in 2015-2016. Regarding passing, all three players place a simialr number of passes as Marchisio. However, all three players put a lot less long passes, suggesting that they place less vertical and penetrative pass to the final third or the switching pass that can switch the ball to the opposite side.
Defensively, Marchisio intercepts a lot more balls (almost 4 times more!) than any of his replacements, suggesting that none of these players have the same positioning and ball anticipation skill. It is consistent with the notion that Marchisio is an intelligent player tactically and this skill is very hard to replace. his absence may also explain why Bonucci has a lot more interception this year compared to last year. Possibly a lot more ball passes through the central defensive midfielder in front of him, and he has to intercept a lot more of these balls.
One surprising finding is that despite being labeled as physically fragile, this year Hernanes tackles as much as Lemina and Marchisio. His tackling success rate is at least 40 percent higher than any other Juventus midfielders.
Comparing to last year, Hernanes seems to modify his game to suit Juventus' style. Offensively he is putting a lot more long passes as a central defensive midfielder. More importantly, he is attempting three times (!!) more tackles compared to last year while intercepting fewer balls. It suggests that Hernanes is putting a lot more physical challenges during the defensive phase. It is wonderful to see a player still tries to transit to a more physical play style to better suit his team despite getting older.
Is Sami Khedira playing better offense this year?
Khedira has been a bright early point for Juventus this year because he has scored in the opening rounds. This year he also seems to get to the box more often. The below statistics summarize his performance in the offensive phase:
He is scoring more goals per minute this year. But this is because he is taking a lot more shots, especially in the penalty area (where his positioning excels and allows him to get himself free in the penalty area). In fact, he needs more shots to score a goal this year. These data is consistent with the notion that this year he is more aggressive in getting into shooting positions, rather than improving his finishing skill.
Why is Juventus less efficient in finishing chances?
Despite creating two more chances every game, Juventus does not score more goals compared to last year. Therefore, Juventus' players are less clinical in front of goal this year. Surprisingly, Juventus also adds one of the world best strikers in Gonzalo Higuain this year.
The statistics tell an interesting story. Higuain scores a very impressive number of goals per minute. In fact, his goals/min rate is so high that it is almost two times higher than any Juventus players in the last five years !!!
But Higuain's impressive finishing rate also highlights that some Juventus are struggling to finish chances. In fact, the three players — excluding Simone Zaza and Alvaro Morata — with the highest goals/min rate last season have decreased their finishing rate this year.
In particularly, despite scoring one goal every four shots last year, Mario Mandzukic has not scored this year. Paulo Dybala also needs four more shots to score a goal this year. In particularly, despite scoring one goal every four shots last year, Mandzukic has not scored this year. Dybala also needs four more shots to score a goal this year. Mandzukic's statistic is particularly worrying because he is taking at least 50 percent more shots this year.
One reason for their poorer finishing rates is that despite Juventus creates more chances; these are not good chances. However, this argument is not likely because Higuain actually scores at a higher rate than when he was in Napoli last year.
One reason for their poorer finishing rates is that despite Juventus creates more chances; these are not good chances. However, this argument is not likely because Higuain actually scores at a higher rate than when he was in Napoli last year. These data argue that Juventus creates better chances for their forwards compared to last year Napoli (who scored more goals than Juventus last year). For Dybala, his poorer finishing rate is not due to his more withdrawn position, because his number of shots and his shot distribution are very similar to last year (data not shown). Therefore, the poorer finishing rate of Dybala and Mandzukic are due to form or confidence.
Although the above data can only provide a glimpse of the game, they highlight some interesting points that are not visible from plain eyes. They emphasize how good a defender Benatia is. They also show that Hernanes is improving his skills to suit Juventus needs better. Most importantly, they suggest that despite adding a world class striker in Higuain, most Juventus attackers have a harder time to score goals this year.
However, some questions remain. For example, we still do not know why Juventus is so good at limiting opponent's shots this year. Answering this kind of problems will need to have better statistics and to complement them with more tactical analyses.
This article is an experiment because I have not done it before, and I have not seen too many people doing something similar (concerning using data to answer a specific question of a team's performance). If it is received well, we will do it again in midseason and at the end of the season. If you know better data source, please also let me know.