Mateo Kovacic: A Statistical Analysis of Who Will Fit in Thomas Tuchel’s Chelsea System

Thomas Tuchel’s arrival to Chelsea Football Club has brought forth many questions, mainly with the players in midfield and how each player will or will not fit into the new system the German manager prefers to use. In this series of articles focusing on Chelsea’s midfield men, Thomas Tuchel will have many decisions to make regarding the best fit for each of his starting XI. The German has so far stuck with Mateo Kovacic and Jorginho, but what are the stats behind the Croatian?

This series of articles used a statistical analysis of the data from the Lampard era during the 2020/2021 season to determine how well each midfielder will fit into the new system, and where each individual will need to improve and/or continue to excel. The first article in this series examined Mason Mount, but how does the 2019/2020 Player of the Year, Mateo Kovacic, compare? The analysis below answers this question and how Kovacic will fit in with Tuchel’s system.

Mateo Kovacic: Individual results and analysis

Mateo Kovacic

Basis Descriptive Statistics

Mateo Kovacic played a total of 1170 minutes and received 4 yellow cards. During this time on the field, he registered 0 goals and 2 assists. Kovacic had 197 pressures, 29 tackles, 13 interceptions, and 15 blocks under Lampard’s management this season. Kovacic has always been regarded as more of a dribbler who is able to beat the press and link the defensive third to the middle third in transitions, but Kovacic has never been known as a goal or assist threat. This is evidenced by Kovacic only registering an expected goal value of 0.6 and an expected assist value of 1.3. Impressively, Kovacic has beaten his expected assists, but he has failed to register a single goal this season and has underperformed the expected goals.

Kovacic completed on average 89.74% of his 789 attempted passes under Lampard, and 71 of those passes were progressive passes, which are defined as a pass that travels 10+ yards towards the opponent’s goal. Kovacic averaged 3.55 progressive passes per game. Kovacic recorded 15 shots under Lampard this season with 1 of the shots being on target, for a shot target percentage of 6.667%. His conversion rate for shots is 0%. Kovacic carried the ball 771 times and 80 of those were progressive carries towards the opponent’s goal. Finally, Kovacic completed 22 dribbles prior to Lampard’s dismissal.

Plots and Correlation Analysis

Kovacic has been criticized many times within the fanbase for his lack of goal scoring and end product. Many reasons abound for why these faulty criticisms exist, so perhaps the below plots will elucidate a new perspective which get fans to see that his role has never been about goals and assists, and that it likely will not be changing anytime soon.

One aspect in which Kovacic has been praised is his carrying, progressive dribbling, and press resistance as a midfielder. He is often criticized for a lack of progressive passing and the final ball, so how does that data look when plotted?

A graph detailing how important Mateo Kovacic is to Chelsea
A graph detailing how important Mateo Kovacic is to Chelsea when looking at his progressive passes compared to shot creating chances

In the above plot is the number of progressive passes versus the number of shot creating actions per each match Kovacic has appeared in this season. The trend in the plot above is that although it is a medium-strength, positive correlation, it is statistically insignificant (t = 1.30, df = 18, p = 0.210, r = 0.293). What this result means is that although Maeto Kovacic is more likely to create SCAs the more he plays progressive passes, there is not a significant relationship between the 2 statistics, and therefore random chance better explains the correlation than any underlying, causal factors.

However, Kovacic is also regarded as a player that uses progressive dribbling/carries with great success, and this was plotted against his number of touches per match. Plotting this data will reveal if a significant relationship is present between the number of times Kovacic touches the ball to the number of times that he progressively carries the ball towards the opponent’s goal.

A graph detailing how important Mateo Kovacic is to Chelsea
A graph detailing how important Mateo Kovacic is to Chelsea when looking at his progressive carries and touches

The more Kovacic touches the ball, the more likely he is to create progressive carries towards the opponent. The importance of this correlation is that it is a high-strength, positive, statistically significant correlation (t = 3.242, df = 18, p = 0.0045, r = 0.607). What this means is that Kovacic is creating more progressive than expected by random chance, therefore he is significantly causing more progressive carries than expected per touch he has on the ball. There is less than 4 one-thousandths of a percent that this relationship is not being caused by random chance.

As mentioned above, Kovacic has been criticized for a lack of actions resulting in goal involvements. However, this can be analyzed in some form by regressing progressive passes to goal creating actions.

A graph detailing how important Mateo Kovacic is to Chelsea
A graph detailing how important Mateo Kovacic is to Chelsea when viewing his progressive passes and goal creating actions

The above plot shows that Kovacic generally is not creating a significant amount of GCAs per progressive pass that he plays. The above plot has a fairly weak, positive, statistically insignificant correlation (t = 0.909, df = 18, p = 0.378, r = 0.209). However, Kovacic is producing a positive correlation for these values, whereas Mount was producing a negative correlation. Although the correlation for Kovacic in the above plot is not statistically significant, it is at least a positive correlation: the more Kovacic plays progressive passes, he is still more likely to create a GCA than to not create one, as evidenced by the positive correlation (r value).

Finally, I wanted to ask and answer how accurate of a passer is Mateo Kovacic prior to Tuchel’s arrival? Below is a boxplot of the pass completion percentage for Kovacic.

A graph detailing how important Mateo Kovacic is to Chelsea
A graph detailing how important Mateo Kovacic is to Chelsea when looking at a boxplot of his pass completion

The above plot shows several key pieces of data: the median, 25th and 75th interquartile ranges (IQRs), the lower and upper bounds of the probability distribution function (PDF), and outliers. The IQRs are displayed by the upper and lower (75th and 25th, respectively) bounds of the grey box, and these values correspond to one standard deviation above and below the median value on the PDF, respectively (this is but one way to display and evaluate the variance around a central tendency, which in this case is the median). The “whiskers” of the plot are the upper and lower bounds of the PDF, meaning that values outside of the “whiskers” are outliers, and those are displayed by the unshaded circles.

The boxplot above shows several things. First, Kovacic’s median pass completion percentage is nearly 91.0%, which is a very high percentage. Kovacic simply does not misplace very many pass attempts. When Kovacic performs one standard deviation greater than the median would predict, his pass percentage is roughly 94.0%, and when he performs worse than the median would predict, his completion percentage is still roughly 86.0%. There is only one match this season in which Kovacic performed poorly enough to create an outlier. Simply put, Kovacic is a very accurate and consistent passer.

Mateo Kovacic striking the ball from difference. Not one of the Croatians best attributes!
Kovacic on top form against Spurs. Credit | Getty Images

Conclusions

Mateo Kovaic is highly talented but he does have aspects to improve upon if playing in Tuchel’s system. First, Kovacic will need to be more involved in the defensive transition phases of play with interceptions, tackles, and blocks. As one of the holding midfielders in the new system, he will be required to quickly hunt the ball and neutralize opponent’s counter attacks. Luckily for Kovacic, he may not have to increase his goals and assists output as he will not be tasked with creating assists as much when playing as a holding midfielder. Kovacic will probably need to provide more progressive passes into the wing backs running the flanks and to any attacking midfielders attacking the opposition’s box. Kovacic will likely be able to keep his progressive carries and dribbles static from Lampard’s to Tuchel’s system.

Kovacic will likely want to create more progressive passes, as mentioned above, but it will be important to have those progressive passes lead to shot or goal creating opportunities for teammates. The pass completion percentage will need to remain constant as well for Kovacic to truly flourish in this new system, as playing the smart, simple, effective pass to keep the slow build up going.

Overall, Kovacic seems to be a fairly solid fit into the new system. He will be tasked with more defensive responsibilities and must raise his output in that regard, but his progressive dribbling, carrying, and highly accurate passing should become a valuable piece to Tuchel’s 3-4-2-1 formation that has been relied upon since the German manager took the reins at Stamford Bridge.

Written by Travis Flock @crossroads_cfc

Edited by Tom Coley @tomcoley49

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