Chelsea play Liverpool on Saturday, just three days after Maurizio Sarri's side beat Jurgen Klopp's high-flying team 2-1 in the League Cup. This time it's the Premier League - the real deal. Sorry, Carabao.

Klopp wasn't happy about that defeat and will be determined to make amends and keep Liverpool's form red hot. He must do so against a genuine title-challenger.

It's the biggest test of Sarri's Chelsea career so far and until this point, he's done pretty well. What will we learn from Saturday's game? Who will come out on top? And where will the game be won and lost?

Why Chelsea look less solid defensively

When playing with a back three last season Chelsea always had three designated defensive players at the back end of the pitch, with the midfield two providing a shield for them. Attacking width came from wing-backs and the ball was moved quickly from back to front, usually focused down the wings to get service into the strikers.

How Chelsea lineup under Antonio Conte, defensive-minded players highlighted

The mentality of Sarri's style of play is entirely different. Gone is the deep defensive line, in its place is one which often sits in the opposition half. With a back four, there are now only two designated defenders (one of which is permanently forward-thinking David Luiz) while Jorginho is the anchor, and is not a defensive midfielder.

How Chelsea may line up against Liverpool

N'Golo Kante must now attack and defend instead of just the latter and with the full-backs higher up the pitch, suddenly there are fewer defensive-minded players adhering to a 'safety first' rule.

Chelsea on the attack

Chelsea no longer divide responsibilities between defence and attack, or provide the centre-backs with a shield. Instead they defend high up the pitch as a unit.

When Chelsea get this right they keep the ball far away from their own goal and dominate the ball, but if both full-backs go forward and someone is caught in possession, they can easily be left exposed. Two centre-backs can end up having to deal with an entire team counter attacking at speed.

How Liverpool's counter-attack can expose a vulnerable Chelsea shape in transition

West Ham were unfortunate not to score in their 0-0 draw with Chelsea last Sunday, creating several chances by blocking and stealing the ball near the halfway line and attacking the space left by advanced Chelsea players. Liverpool pose far more of a threat and could conceivably smash-and-grab before Sarri's side have settled in.

Battle of the full-backs

Marcos Alonso might be listed as a left-back but is more like an attacking left-sided forward, frequently touching the ball inside the opposition penalty area.

Marcos Alonso touchmap vs Arsenal credit: OPTA

He gives Chelsea a fantastic attacking outlet but can leave them vulnerable to counter-attacks - something Liverpool will be looking to take advantage of. In recent weeks Jorginho has been dropping into the space left vacant by Alonso but with Mohamed Salah lurking and Firmino marking Jorginho, further caution is required.

Liverpool's full-backs are equally prone to dashing forward to overlap the narrow front three. This is where Andrew Robertson and Trent Alexander-Arnold touched the ball in Liverpool's 3-0 win over Southampton:

touch maps

Eden Hazard's free role on the left of Chelsea's attack will allow him to float around the space that Alexander-Arnold will abandon, while Willian - who has created the most chances (17) in the league this season can run in behind Robertson.

The key for both teams is getting the balance right between defence and attack. One misplaced pass at the wrong time could lead to those wide spaces being used to create chances.

Jorginho is the heartbeat

At the heart of Sarri-ball 2.0, is Jorginho, also the heartbeat of Sarri-ball 1.0. No player in the Premier League has touched the ball more times (749) this season than the Brazilian, who has achieved this operating in the six position in Chelsea's 4-3-3, dropping deep between the two centre-backs to find space, receive the ball and set the tempo of Chelsea's passing.

Nearly all his touches take place in the same small area of the pitch:

Jorginho touchmap vs West Ham credit: OPTA

The Liverpool player closest to him in touches (589) and passes (689 - also the highest in the league) is James Milner (524 touches, 407 passes). In contrast to Jorginho, Milner's touches are all over the pitch, as below against Spurs:

James Milner touchmap vs Spurs credit: OPTA

And here against Leicester:

James Milner touchmap vs Leicester credit: OPTA

However, Jorginho makes more attacking passes from these positions. His 109 passes into the final third are significantly more than Milner's 75, and show why Liverpool must look to limit his influence.

Chelsea's midfield don't need to take Milner out of the game to stop their slick passing game, but Liverpool can disrupt Chelsea's game by sticking a man on Jorginho - similar to the way Roberto Firmino marked Man City's Fernandinho out of games last season - and prevent him from pulling the strings.

Winning the ball back

Liverpool's all-action, always-forward style of play means they are more likely to give the ball away than Chelsea. The possession stats reflect this - Chelsea average 65.7 per cent and Liverpool 55.4 per cent - but Klopp's famous gegenpress is part of the plan.

In Klopp's teams, the players run at their opponents trying to force opportunities until they lose the ball, at which point they must win it back as quickly as possible. Liverpool try to start counter-attacks high up the pitch as opposed to sitting deep and springing the trap, as in a Jose Mourinho style mid or low block.

Chelsea also press high up the pitch but are more cautious with their approach play and wait for the right time to thread passes in behind. Again, the stats reflect this: Liverpool make 18.8 tackles per game, while Chelsea make 12.5.

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These numbers might be skewed as Chelsea have come up against three deep highly defensive opponents in Newcastle, Huddersfield and Cardiff, while Liverpool have played Southampton, Leicester, Spurs and West Ham - none of which spent 90 minutes sat in a deep 5-4-1. Nevertheless, the strategy is clear. Battering into a door will eventually force it to buckle and splinter. That's when Mohamed Salah makes his entrance.

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Chelsea won't have as much possession on Saturday as they've enjoyed so far this season and face a far more ferocious pressing opponent than anyone they've played so far under Sarri. They must be hyper-concentrated when making passes across their own midfield and ensure there are clear passing options when Liverpool lose the ball to shift danger instantly and safely, preventing the dreaded gegenpress from tearing the back four apart.

How the game might look

This is Chelsea's first proper test. The last title-challenging team to employ a high defensive line in a 4-3-3 shape against Liverpool was Man City - Liverpool won three out of four games against Pep Guardiola's side last season, with a 9-9 aggregate scoreline skewed by City's early 5-0 win.

Liverpool will create chances. Whether that's from set pieces (Liverpool have scored from five already this season) or open play is impossible to predict but statistics show that 12 per cent of the shots they have taken come from inside the six-yard area. That suggests the quality of those chances will be high - another concern for a vulnerable-looking Chelsea defence. By contrast, only one per cent of Chelsea's shots have come from inside the six-yard box.

If Chelsea don't get the balance right and Eden Hazard fails to deliver another star performance, it could all go very wrong very quickly. It's practically guaranteed to be entertaining.