Chelsea's tactical headache deconstructed: The problems facing Sarri-ball - and why N'Golo Kante will not be moved

In defensive phases the shape can change to a 4-5-1 if the wingers do the defensive work required. The setup is very structured and depends on players who understand the tactical demands and are suited to their individual roles. Everyone knows how Chelsea play now.

Marking Jorginho

In the first phase of build up, everything goes through Jorginho. He acts as the link in all Chelsea's passing, dropping between the centre-backs, offering a safe diagonal pass backwards for the two eights and able to switch play from deep to an advancing full-back to get Chelsea up the pitch.

All anyone need do to suss out how influential Jorginho is look at Opta passing statistics.

The solution is to mark him. In teams that play a 4-2-3-1, the 10 is the obvious choice for this because of the strata that Jorginho plays in ("between the lines"). Arsenal changed their formation to a 4-4-2 diamond for the win on Saturday, with Aaron Ramsey assigned the task of following Jorginho wherever he went.  

Everton were one of the teams who worked this out early (Man Utd the first) and apply their analysis successfully, having Gylfi Sigurdsson stay next to Jorginho or stand directly in his cover shadow, making a pass to him risky. 

Everton secured a 0-0 draw, Spurs marked Jorginho in the next match and won 3-1. Chelsea scored an average of 2.25 goals per game before the Everton match in November, and since, they've managed only 1.18 per game.

Jorginho was an essential part of Sarri's Napoli team too. He allows Chelsea to maintain this shape and these passing lanes:

If you remove that one link, all of Chelsea's play is forced into wide areas, as you can see from the average positions.

Isolate Jorginho and Chelsea's first phase of buildup is ruined. There's no way Sarri isn't wholly aware of this but why would he compromise the system and shape that brought him so success he was offered the Chelsea job in the first place?

Curbing Chelsea's creativity

The arrival of Sarri was good news for David Luiz, who has become one of Chelsea's most important creative players. Centre-backs aren't usually man-marked, which means they are free to distribute the ball as they wish - Luiz's long range passing is superb.

This exact pass put Pedro clean through on goal, played onside by Arsenal's left-back Sead Kolasinac. A possession-based side like Chelsea would usually depend on the creativity of the attacking midfielders to find openings, but a midfield of N'Golo Kante, Mateo Kovacic and a man-marked Jorginho needs a bit of help from someone with ideas.

Luiz is perhaps the only footballer in the team prepared to hit direct, vertical passes to catch out teams defending against Chelsea's never-ending horizontal passing.

The solution to this is obvious too: force Chelsea to pass the ball to their right flank, away from Marcos Alonso and Luiz, towards Cesar Azpilicueta, Antonio Rudiger and Kante, who are less artistic distributors of the ball. That's exactly what Arsenal did.

Possession without penetration

Opposition teams are entirely happy to let Chelsea have the ball because that's the best way to defend against them. With build-up play spoiled because Jorginho is marked and without a striker capable of causing damage, they're so predictable in the final third that teams can defend patiently behind the ball until Chelsea run out of ideas, try a shot from 20 yards or cross the ball into nobody, turning over possession.

Chelsea's attacking shape leaves them vulnerable to counter-attacks, which makes sitting deep and waiting for the ball a safe option for success.

Eden Hazard is best when allowed to roam from his starting position on the left of a forward three but when stationed as a false nine, doesn't see enough of the ball. When he drops deep to get involved, Chelsea are left without a player to aim crosses to in the box and his natural inclination to drift to the left side means the centre of the pitch is left vacant.

And so, Chelsea work the ball wide either by choice or forced to by the defending team, reach the end of the corridor and then have no option but to pass backwards, then sideways, then backwards.

Chelsea's players are being marked out of the game, which means the most creative are being neutered by the entire team's predictability.

We've seen this happen to other managers in recent seasons. Jurgen Klopp's Liverpool employ the same shape as Chelsea, but move the ball through the lines more quickly and employ a more frantic forward press. It took Klopp several transfer windows and three seasons of coaching to get his side looking the way he wanted.

In the days before Naby Keita and Virgil van Dijk Liverpool had similar struggles in the Premier League, with teams like Burnley sitting back, denying space and coming away with 1-0 wins. With time Sarri can construct a starting XI in his own image too but that in itself is a problem to fix - will he be given time and money to buy new players to fit a system, or does he need to change the system to fit the players?

Is N'Golo Kante out of position?

Kante is one of the world's great midfielders. He won the Premier League with Leicester and Chelsea as a central midfielder in a midfield two, running around the pitch with such energy and making so many tackles and interceptions that Claudio Ranieri remarked it was like there were two of him on the pitch.

Sarri's midfield three fundamentally needs a player who to set the passing tempo and who is able to receive the ball in tight spaces, turn a corner and bring others into play, hence Jorginho. The two eights must be in position to link passing through the middle, cover in defence and attack the halfspaces in the final third. Kante can't play as a six so he has to be an eight.

The thing is, Sarri cannot drop Kante because he is one of Chelsea's very best players. But Kante isn't the best at either of these roles...

Kante can play the box-to-box role asked of him in Sarri's system but creates chances by winning turnovers and barging his way past players. Without another midfielder on the opposite side of the pitch capable of unlocking a defence and with Hazard's creativity absent due to his positioning, there's no cutting edge in the final third.

Were Sarri to introduce a formation that has Kante in a deeper midfield role, the shape would change to a 4-2-3-1.

This fundamentally alters the passing lanes and options for build up that Sarri wants. The 4-2-3-1 is a great counter-attack formation (Liverpool use it often this season) but Sarri wants control of the game by having possession of the ball. Switching to two sixes and a 10 doesn't suit this.

Most obvious weakness is that by moving a player from six to 10, buildup play cannot go through a central pivot and instead must be shifted wide or vertically.

Teams tend to defend against this shape by sitting at halfway or slightly deeper, crowding out the 10 and forcing passes out wide... sound familiar? Vertical passes often result in turnovers of possession, which means the attacking team doesn't have total control of the ball, which means a manager has less control over the outcome of a match. Sarri wants to limit variables since that's how his teams gain an advantage, never relying on the luck of a dice roll. 

The system is fine, the players are at fault

"This defeat was due to our mentality, more than anything else," said a furious Sarri in his post-match interview. "This is something I can't accept. This group of players are extremely difficult to motivate."

Arsenal were quicker to close down Chelsea, and from kick-off showed more energy and aggression all over the pitch. Without maximum effort or at least a matched desire to win, tactical setups can have little effect on the outcome of a match between two groups of hugely talented players.

When teams play with a high defensive line as Sarri's does, the first line of press is crucial but too often Arsenal were able to escape the attentions of Pedro, Willian and Hazard. Arsenal stayed narrow in their own half and had a striker stay wide to offer an out-ball - Sarri shouldn't have had to explain to his players how important it was to cut this pass out:

When players were caught out of position others failed to react and fill the gaps. Without that burning desire to hunt and win the ball back, Sarri-ball doesn't function as it should. The attacking shape leaves the defence vulnerable in transition - if the attackers don't defend with the right intensity in the right places, the building falls down. 

Attackers can sometimes get away without defending if they're producing the goods at the other end but that isn't happening. Hazard is wasted as a false-nine because he can't get on the ball, and though Willian has created 59 chances this season - the third most of any player in the Premier League - only three of these have been converted (three assists) and he has only scored three goals himself.

Pedro has seven goals and only one assist. Gonzalo Higuain might make a big difference to Chelsea, free up Hazard to go wide left and Willian wide right, but the problems will remain unless those forwards do the unrewarding hard work necessary to make Sarri's system work. Mourinho and Antonio Conte were only able to win things with the same group of players when in a deep, defensive counter-attack setup - the same problems with defending from the front have been there for seasons. 

Sarri might be exactly the coach to build a team which wins by playing truly attractive football but to do that he needs time, something Chelsea don't have a history of affording. There's no panic right now - Chelsea are fourth after all - but there are clear problems that need addressing at Stamford Bridge and it is interesting that Sarri dropped his friendly, warm media character to dress down the players after the humbling defeat to Arsenal. Chelsea lacked bite at the Emirates, Sarri has started baring his teeth.