Tactical analysis: Liverpool 1-1 Chelsea
August 28th, 2021.
The media narrative around the Liverpool versus Chelsea match had one central idea: that it holds the agency to elect Manchester City's antagonist, the team that will contest for their title. The odds of both teams winning the league were almost identical across various bookmakers, and they were evenly matched in terms of squad quality despite Liverpool's inactivity in the latest transfer market due to a Covid-related economic downturn. However, there is something to be said for squad depth. Buoyed by their healthy financial books, Chelsea have outlaid to the tune of €367mn in the last two transfer windows (per Transfermarkt) on recruitment, including marquee signings in the forms of Timo Werner, Kai Havertz and most recently, Romelu Lukaku.
The match
Having gone down to ten men at halftime, Thomas Tuchel acted swiftly to modify Chelsea's shape in order to counteract the effects of their numerical disadvantage. He took off Havertz and N'Golo Kante (injury) for Thiago Silva and Mateo Kovacic respectively. In doing so, Chelsea's defensive structure mutated from a 5-2-3 to a 5-3-1 low block (when out of possession) spearheaded by Lukaku, who theoretically embodied an outlet in transitions, with Mason Mount slipping into the midfield line. It was the blueprint for how they achieved their tactical objective: frustrate Liverpool and thus, prevent them from winning—but if a penetrative opportunity emerges, leverage it.
Data
Disclaimer: unless otherwise specified, all the stats are StatsBomb data via FBref.
Throughout the game, Chelsea allowed 23 shots - four more than Norwich, and five fewer than Burnley when both sides faced Liverpool this season - but their xG/shot conceded of 0.05 was twice as good as theirs. It's an indication that, although Chelsea conceded a high volume of shots (influenced by game state), the quality of those shots were low. One caveat to interpreting this data as Chelsea's achievement is the debatable utility of the Expected Goals metric in an insignificant sample (and Chelsea's pronounced superiority squad-wise in comparison to those teams, albeit with one man fewer than them). But in this case, it aligns with the objective analysis of the match.
Interestingly, Chelsea made more blocks (25) than Norwich (16) and Burnley (19), but only five of them were shots (Norwich and Burnley blocked seven and nine shots respectively). One of the reasons for this is that they bettered the forenamed teams in blocking Liverpool's passes (20), which may indicate that they found more success in trying to halt their advance to high-value shooting positions. Rather than treating the symptoms of the problem, they identified its cause and stamped it out.
It's worth noting, however, that Liverpool completed more passes in Chelsea's 18-yard box (18) than they did against Norwich (14) and Burnley (15). One stat that caters to the "eye test" is in the pressure metric. Chelsea applied more pressures in their defensive third (68) than they did in the midfield third (39) and attacking third combined (10). It is also reflected in their PPDA of 28.09 (Per Understat). What this means is that Chelsea practised a form of "spatial control": being fully aware of the coverage and compactness conundrum further aggravated by their numerical inferiority, they relinquished territorial control in vast swaths of the pitch that are, by and large, of less strategic value, perhaps a bit too much of it (a circumstantial factor), and channelled their energy into the protection of the half-spaces and the central zones, or the zone 14, to be precise.
Chelsea's impenetrable defence
As shown in the image above, Chelsea bore a compact shape for most of the second half. (Alonso is just out of view, on the right side of the screen; he adjusted his positioning to keep Salah, who provided "single width", at bay.) The distance between the second and last lines of their defensive block was at an optimum, as was the case with the spacing between each player in the two defensive units. Because of this, they had increased "access" to the ball and were also in a better position (if one player were to get beaten, his teammate would be within proximity to support him) to fend off Liverpool attackers.
Mount, Jorginho and Kovacic constituted the midfield triumvirate, which functioned as a spring; they shifted across to the ball side to equalize an overload, and retained their shape in the central areas, to either block the passing lanes, or "collapse" on the opposition; all the while they screened the defence. The back five—staffed by Cesar Azpilicueta (RWB), Andreas Christensen (RCB), Thiago Silva (CB), Antonio Rudiger (LCB), and Marcos Alonso (LWB)—provided cover and balance, and especially excelled in one-on-one duels with their opponents. Christensen and Rudiger, both of whom were assigned to the wide centre-back positions, were instrumental in repelling Liverpool's invasions of the half-spaces. Particularly in the case of Christensen, he exhibited an intuitive awareness of Sadio Mane's counter-movements and Andy Robertson's underlapping runs. And with the help of Azpilicueta, the experienced Spaniard with whom he worked in tandem, he was able to foil their goals.
Pressing Triggers
In the second half of the game, Tuchel's Chelsea coalesced into a low block from which it sprung to sporadic counter-attacking situations but were inclined towards pressing based on specific triggers notwithstanding. Some of which were (a) the half-spaces, (b) the furthermost patches of the wide areas, (c) player profile, and (d) closed body orientation.
Below, having decoded Jordan Henderson's body language, Kovacic anticipated his pass to Trent Alexander-Arnold and began to gain ground on the Liverpool fullback, with the intent to engage him. He does, but Alexander-Arnold decided to play a safe pass to Matip. Kovacic's press was triggered by the full back's occupation of the right half-space, a recurring sequence of the match.
For context, Liverpool clustered around the pitch in a sort of 2-3-5. The last line; Virgil Van Dijk and Matip, the second line; Henderson (he covered the higher placed Robertson), Fabinho and Alexander-Arnold, and the third line; Robertson, Mane, Diogo Jota, Harvey Elliot, and Mo Salah. It must be admitted that the system was anything but static, it was characterised by rotations between Mane and Robertson; between Trent and Elliot; and between Salah and Elliot.
The ball-carrier, who happens to be Alexander-Arnold in this situation, took a liking to move infield, in the right half-space—the vertical corridor in which his crosses had a significantly higher success rate. To achieve this, Salah drifted wide to stretch out the seam between Rudiger and Alonso, and Elliott, knowing fully well that it was the game plan, took up strategic positions—in the inside high channel, the pocket of space adjacent to the "strong side" midfielder (it changed in real-time), and behind the midfield line—to disorient and ultimately, sever Chelsea's defensive unit. But Chelsea recognised the threat and dealt with it, and it was on this platform that Kovacic succeeded in driving back the Liverpool players in those zones.
Here, Kovacic jumped out to pressure Thiago Alcantara (the ball carrier)—his efforts were directed at diverting the play to safer areas, or better yet, force a turnover—which acted as a cue for Rudiger and Alonso to undergird him by shrinking the space, and in the case of the former, getting tight on his man. As a consequence of this, Salah ran across the block to attack the vacated space, but Silva, as planned, was present to eliminate the danger. On the left-hand side of the screen, Lukaku has the relay player (Fabinho) in his cover shadow to deny a switch of play.
As soon as the ball left Henderson's feet travelling in Mane's direction, Azpilicueta geared up himself to put pressure on the winger. Three important factors came into play: (1.) Henderson's body orientation betrayed his intent. (2.) Azpilicueta judged the speed of the ball and reasoned that it was slow. (3.) The activation of a system-based trigger; initiate a press in the wide areas (determined by the height) and use the touchline as an extra player.
But beyond the microscopic elements of the situation, in that it's an epitome of the bigger picture, there were noticeable patterns that would make for interesting reading. Henderson offered himself as an exit option to Mane, while Robertson threatened the Chelsea defence with an underlapping run, which gave shape to a wide triangle. For a moment, it appeared that they have secured an overload. The Chelsea players then—Azpilicueta, Mount and Christensen—became aware of this developing situation, and reacted. They shuffled across to the ball side in a way that is measured, to cancel out the numerical superiority (3v3). And while Azpilicueta did the pressuring, Mount redirected his steps to ensure cover behind him. Christensen, on the other hand, stood on his toes in anticipation of Henderson's overlapping run.
The characteristics of Chelsea's medium/low block
Moments before, Kovacic approached Alexander-Arnold, who returned the pass to Henderson. Upon the midfielder's reception of the ball, Lukaku pressed him to prevent him from switching the play. Being conscious of the physical reality in front of him, Henderson played it back to Alexander-Arnold, and again, Kovacic engaged him. This time, however, Elliot's movement dragged out Jorginho, effectuating the pocket of space in the middle of the park. Fabinho walked into it with ease, and Alexander-Arnold found him with a simple pass. Once he collected the ball, though, Mount and Jorginho closed in on him, and he felt compelled to play a backwards pass to Matip.
Liverpool circulated the ball between their centre-backs and rolled it to the "weak side" where Mane dropped deep to receive the ball on a half-turn in the left half-space. While he attempted to take on Mount, he almost ran himself into the Chelsea wall, before laying off a pass to Jota, who was encircled by the Chelsea players. And sure enough, he immediately opted for the out-ball to Robertson. It was deja vu all over again.
Chelsea, in their 5-3-1 low block, had the license to access the five vertical corridors—the left flank, the left half-space, the central zones, the right half-space and the right flank—when required. Were Liverpool to have possession of the ball in the creation phase, for instance, the back five in conjunction with the midfield three would prioritize the imaginary line which ran the full breadth of the half-spaces. In contrast, the area of interest changed, say, were their opponents to progress the ball down the right-wing: the opposite wing would be abandoned temporarily.
In the same chain of possession, Liverpool applied themselves to horizontal passing. They moved the ball from one side of the pitch to the other, aiming to exploit the openings that may ensue during the shifting process. But Chelsea saw to it that they didn't leave any gaps in their block as they covered ground, acting on well-defined reference points: the ball, the opposition, and crucially, their teammates.
Alonso adapted his starting point to be within touching distance of Salah. As a direct result of this, a gaping hole opened up behind him which Alexander-Arnold was eager to attack; it's axiomatic that Salah wanted to participate in a combination play with him, yet the move fell apart before it began. Within the few seconds that the ball travelled to Salah, Chelsea regained their shape. At first, Rudiger was tailing Elliott, simply because the Liverpool midfielder suggested that he was free to receive the ball between the lines, but Henderson didn't utilise the vertical option. Instead, he chose the relatively easy sideways pass.
For Rudiger, it meant that he now had to move sideward—to the right—so he can watch Alonso's back. Kovacic's role in this passage of play was a celebration of singularities: track Alexander-Arnold's run in the half-space. He went on to press him, which, coupled with Salah's suboptimal pass, led to the dispossession. From there, Kovacic played a one-two pass with Alonso, and it was how Chelsea registered one of their aperiodic box entries in the match.
Elliot and Alexander-Arnold were isolated from Liverpool's attack, and that being the case, they exchanged passes between themselves at a languid pace. To correct this, Fabinho walked towards them to forge a triangle, thereby opening up a passing angle. The moment Alexander-Arnold passed the ball to him, he played it to Elliot. Seeing that Liverpool have consolidated possession (Salah pinned Alonso), Jota dropped into space to receive the ball from Elliot. At which point Jorginho, Kovacic and Rudiger tried to hem him in, and he was forced to make a hurried decision; he bounced the ball to Matip in the last line. Liverpool couldn't infiltrate Chelsea's block once again.
In this situation, Chelsea were determined to maintain their compact shape, and thus protect the central areas. The wing-backs were virtually placed wide apart owing to the absence of Liverpool forward players in the channels, and the threats posed by those in the flanks. Salah was in a potential 1v1 situation with Alonso, and on the other side, Robertson was available for a crossfield pass. Conversely, the three midfielders contracted themselves into a narrow frame, matching up with the back three in width. It rendered Liverpool's target, that is, to penetrate the structure, impossible.
Moments later, Elliot played a simple, yet effective pass to Salah (he was in a favourable position). Alonso showed him outside, as expected, but Salah made an effort to cut inside. And Kovacic, who was closely monitoring the situation, impeded him. He responded to it by underhiting a pass to Elliot with his laces, which almost got intercepted by Jorginho. Salah couldn't make the most of the opportunity, and consequently, Liverpool were chased out of the block.
The individual battles were a pivotal factor in determining the outcome of the match. It's true that Chelsea functioned as a cohesive defensive unit, but their contributions to what can be perceived as a victory on their part, as individuals, cannot be overemphasized. One may have to avoid colloquial terms in writing, especially the ones that only exist within the borders of Urban Dictionary, but permit me to say, Christensen "pocketed" Mane.
When Chelsea had the ball
One of the natural advantages of compactness in a team's framework when out of possession in the medium and low block phases of the game is the network of connections between players that can, if used properly, translate to the possession phase. Jorginho and Kovacic, in particular, exemplified these principles. And it was certainly not purely on a tactical level. Their abilities to keep the ball under pressure (press resistance) were of paramount importance.
Christensen blocked Robertson's return ball to Mane, which resulted in a turnover. Soon after that, Kovacic picked up the loose ball and displayed a sense of calm as he snaked his way through Liverpool's counterpress—orchestrated by Mane, Jota, Robertson and Henderson—before completing the pass to Azpilicueta rather clumsily (Jota tried to steal the ball from him).
At face value, there isn't much to be marvelled at, in regards to the action. But beneath the surface lies something worthy of contemplation. First, in view of the fact that the dangers of losing the ball so close to goal were real, Kovacic's composure was impressive. Second, his time on the ball—the precious seconds—allowed Azpilicueta to get himself into a position where he can receive the pass without being subjected to immediate pressure.
Similarly, Jorginho was immediately surrounded by the Liverpool players after a turnover had occurred. Mane timed his movement to keep Azpilicueta in his cover shadow, while Jota was intent on using his body to close off the passing options. But the Italian midfielder didn't panic. Instead, he casually turned Robertson around, and put his body between him and the ball and drew a foul. That's experience.
Final words
The quotes from one of the commentators who worked on the match, encapsulates it, "if good defending is an art," he said, "we've seen it in this second half."
written by David Ezechimere (@Rhalbraum on Twitter)
