Partenopei: an in-depth analysis of S.S.C. Napoli

In this article, I provide a data-driven analysis of Napoli from this season (up until 12th March). The particular aim is to go beyond exclusively analysing raw outputs, and to apply a possessions model with the aim of providing insight that can help inform decision making.

A quick introduction of this model

By combining Opta event data, we can create a definition of an individual possession, which involves all of the events that happen between a team gaining control of the ball and conceding possession of it after.

This article by Sam Green outlines the basics of a framework which has since been modified, with a more in-depth write-up of this model to be published in the near future. In the meantime, the shortened version is that these events make up small subsets called sequences where a team is actively in possession of the ball. A team ends a sequence when they concede control of the ball – getting tackled or taking a shot for example.

Sequences don’t necessarily end a team’s possession of the ball, however. If you take a shot but it is saved and goes behind for a corner, you have ended one sequence but begun another. Possessions are built up of all a team’s sequences – as there can be multiple sequences per possession.

This means that both teams will share the same number of possessions (or it will be off by one or two depending on who starts the game/half) but won’t likely share the same number of sequences.

Now, let’s apply this framework to analyse Napoli…

Style

– Napoli have a dynamic playing style that focuses on a high number of passes but is also rather direct
– They move the ball fast, and progress it high up the pitch, but the movement up the pitch itself is not overly quick

Maurizio Sarri’s side often build from goalkeeper Pepe Reina and play through defence into midfield. They average 4.5 passes per sequence, the 3^rd highest in Europe.

Most passes per sequence

Based on the ‘top five’ European leagues, 2016/17

Additionally, Napoli make the most progress towards goal per sequence in Europe, moving the ball 18.4 metres on average, marginally ahead of Arsenal who move 18.3 metres.

Despite Sarri’s side being possession-based and progressive with the ball, they are not necessarily one of the more direct teams in Europe.

Direct Speed – defined as a side’s progress divided by the time of the sequence – is a useful tool to assess how fast the team moves the ball up field. Despite moving the ball the quickest and being the most progressive side in Europe, Napoli aren’t the most direct.

The image below is a good example of Napoli’s style of play. They progress the ball 53 metres up field – 250 metres in total – and the overall length of the sequence is just under 33 seconds. This gives them an overall speed of 7.6 metres per second but a direct speed (progress towards goal over time) of 1.6 metres per second – showing that they quickly move the ball, although they are not quick to move it directly up the field.

Shooting

– Napoli’s attackers are predominantly right footed, and the main attackers each display different tendencies. For example Lorenzo Insigne often shoots from range, and a significant number of Jose Callejon’s chances are assisted from crosses
– Their fast-paced attack may be the reason for the side taking very few headed shots

Napoli are incredibly efficient in turning sequences into shots. They’ve taken the highest number of shots per match in Europe this season (17.72) and end 11.1% of their sequences with shots (European average is 7.5%). In Serie A only Roma end their sequences with a shot more often (11.6%).

Napoli’s main shooting threats are Marek Hamšík, Lorenzo Insigne, Jose Calléjon and Dries Mertens in a 4-3-3 formation, where Mertens is central and flanked by Insigne and Callejon. Hamšík plays as the most advanced of three central midfielders.

How Napoli create their chances

Napoli have had to rely on these four for the majority of this season, with Milik rupturing a cruciate ligament and Gabbiadini recently joining Southampton, although he rarely featured.

Below are the shot maps for these four players.

Mertens takes the best quality shots out of the foursome; often shooting from central areas and only had four headed shots from open play this season so far. He’s not scored one open play goal from outside of the area, and has been most prolific poaching in the central area around the 6 yard box.

Calléjon seems to favour shooting with his right foot, taking just a quarter (15) of his shots with his left. His shot map displays a couple of his tendencies when it comes to shooting. He sometimes cuts in and shoots from the edge of the area, or takes shots after a cross within the box – a staple of Napoli’s attacking plan where they look to play a cross in behind opposition defences to the free man on the far side.

Insigne’s lack of shots from central areas close to goal is reflected in his low xG per shot total. Again, he takes a low number of shots with his left foot (14/94) but this is a likely consequence of a player cutting inside from the left. He also has a tendency to let fly from long range, as highlighted by the numerous shots from outside of the area.

Finally, Marek Hamšík’s actual goal total exceeds his Expected Goals – even considering the low quality of chances he’s had this season – he’s scored one in five compared to his Expected Total suggesting he should have scored one in 14. The majority of his shots are from central locations outside of the area, but he’s profited most from the shots to the left of the six yard box.

Hamšík’s real strength this season lies in his creativity. His 60 chances created is a team high, and only Atalanta’s Alejandro Gomez has more this season.

From which foot are players taking shots?

All non-headed shots

The obvious thing to note is the deficit in predominantly left-footed attackers – a useful piece of information for defending teams.

The low volume of headers that they take and the physical nature of these players (small, quick) means that looking to play more agile defenders could help neutralise Napoli’s threats.

The full backs

– Hysaj and Ghoulam play quite different roles within the team
– Ghoulam is far more attacking compared to the average left full back in Serie A
– Hysaj is markedly less advanced in his positioning, and pinches in a bit more centrally
– Scrutiny using video or tracking data may highlight how Napoli cover Ghoulam’s position on the pitch when he moves further forward

Compared to other Serie A full backs, Ghoulam and Hysaj are markedly more advanced in their positioning (and often wider). The maps below compare their ball touches to others in the league playing in the same position, including only in-possession and in-play touches (i.e. no set pieces/corners/defensive actions).

Defence

– Napoli concede fewer shot per possessions than the average European side
– They have conceded the majority of their shots from open play, but the conversion rate of these chances is low
– The conversion rates from direct free kicks, set plays and corners are quite high – so there may be opportunities to exploit them at these situations

Pressing the ball

Based on opponent’s metres progressed per sequence, Napoli are a good pressing team. They rank 18^th across Europe for this metric, but first in Serie A.

Exactly how Napoli press opponents is not covered here, but this article from Johannes Harkins provides an in-depth explanation of different approaches in how we can quantify pressing.

The chances Napoli concede

Looking at the shots that Napoli concede in open play, they’re doing a good job of restricting the opposition to converting just 9% of their open play chances. The conversion rates for corners, direct free-kicks and set plays are all in the teens – but the shot volumes on these are low and this only takes into consideration the situations that result in shots.

Looking at a breakdown of the quality of these chances, Napoli are perhaps a tad unfortunate to have conceded 19 goals – with the total xG of the chances they’ve conceded from open play this season sitting at 16.62

To recap…

Considering all of the analysis above, it’s best to synthesise all of this information into a few key points that can be communicated quickly and easily. Many of these points can be used as the basis for creating a game plan for when playing Napoli, and provide some helpful pointers on situations to research a further. To recap, these key points are:

Style

– Napoli have a dynamic playing style that focuses on a high number of passes but is also rather direct

– They move the ball fast, and progress it high up the pitch, but the movement up the pitch itself is not overly quick

Shooting

– The Napoli attackers are predominantly right footed, and the main attackers each display different tendencies. For example Lorenzo Insigne often shoots from range, and a significant number of Jose Callejon’s chances are assisted from crosses

– Their fast-paced attack may be the reason for the side taking very few headed shots

Full backs

– Hysaj and Ghoulam play quite different roles within the team.

– Ghoulam is far more attacking compared to the average left full back in Serie A, and is involved less within the left back zone

– Hysaj is markedly less advanced in his positioning, and pinches in a bit more centrally

– Scrutiny using video or tracking data might highlight how Napoli cover Ghoulam’s position on the pitch when he moves further forward

Defence

– Napoli concedes fewer shot per possession than the average European side

– They have conceded the majority of their shots from open play, but the conversion rate of these chances is low

– The conversion rates from direct free kicks, set plays and corners are quite high – so there may be opportunities to exploit them at these situations