Where do you go from here? In 2012, Chelsea sacked their concept manager, Andre Villas-Boas, handed the reigns to a club legend, Roberto Di Matteo, finished miles off the pace with 64 points then promptly went out and won the Champions League. In 2021, Chelsea sacked their club legend manager, Frank Lampard, handed the reigns to a concept manager, Thomas Tuchel, finished miles off the pace with 67 points then promptly went out and won the Champions League. It took Tuchel 123 days to hit that high point and he did it by focusing first and foremost on defence. In 19 Premier League games under Tuchel, Chelsea gave up more than one expected goal twice: firstly against West Brom in the freakish 5-2 defeat and latterly against Manchester City, two games from the end of the season in a match they won regardless. The difference that Tuchel made to the team was as stark as it was swift and they were clear second best behind Manchester City in the back half of 2020-21. In their first ten game phase under Tuchel the team closed everything right down. The attack was yet to gel together but the defence gave up a remarkable four xG and conceded just two goals. By season’s end Chelsea’s Tuchel era metrics were in hailing distance of Manchester City with a +1 xG difference per game across his reign (for the same period City were +1.2) with the impressive side still mainly defence (0.56 xG against) while at least in terms of process, the attack had perked up and landed at a decent 1.56 xG per game. Only two teams have put up metrics of this ilk in recent seasons: Liverpool and Manchester City. It may be a short spell, but the strong indicator here is that Tuchel has managed to organise Chelsea’s high quality, high potential squad into a shape that is capable of contending. Lampard had the makings but not the execution, Tuchel had both. So what did he do to harness the talent in this squad? First up the obvious switch from Lampard’s general 4-3-3 and variations towards a distinct 3-4-3. This had the instant benefit that if you were a centre back, then welcome aboard, you now had a great chance of getting good minutes regardless of what had been happening so far in the season (hello Antonio Rüdiger, Andreas Christensen), ditto anyone who had experience of playing wing-back, let’s say in a league winning side playing a similar formation (come on down Marcos Alonso) and anyone called Mason Mount, mainly because he’s literally the ideal player for any team playing any formation, something on which both Lampard and Tuchel agreed, more later. Here’s the minutes splits across the squad: Chelsea had a relatively injury-light 2020-21 (and the squad to survive it too) so the balance between the Lampardis and Tuchelistas is fairly reliable to spot. Each manager loved Mount, Edouard Mendy, Timo Werner and Reece James–these were a core four and come rain or shine, their managers picked them. More Lampard favoured were Ben Chilwell (a bit), N’Golo Kanté, Kurt Zouma and Tammy Abraham while Tuchel was big on César Azpilicueta, Jorginho, Rüdiger, Christensen and Alonso. Kanté and Chilwell get a pass here too really as once the business end of the Champions League kicked in they were solid picks in that tournament, as was Kai Havertz. The risk players for this squad are quite clear: Abraham was losing minutes to Olivier Giroud, who has now left and has likely seen his potential position gazumped entirely by Romelu Lukaku (a transfer for him seems imminent too). Hakim Ziyech struggled to see pitch time for either manager last season and at the moment looks like the big miss/square peg among the high class attackers purchased in summer 2020, despite quite good statistical contribution when on the pitch. Christian Pulisic saw more game time at the back end of the season, enough to think he’s likely to stick around and feature, while Callum Hudson-Odoi remains a statistical marvel but repeatedly flits in and out of favour whoever is in charge. Seriously, Hudson-Odoi is fascinating. Snooping around earlier in the summer I spied this and tweeted it: More than 1000 minutes, more than 2.4 OPEN PLAY key passes per 90? 3 qualifiers in the PL, De Bruyne, Grealish and… Hudson-Odoi Then when I was poking at our new OBV model numbers for this article, he leapt off the page again, albeit predominantly in the Lampard era where he was clocking 0.56 OBV/90. This was right around better players in the league, albeit in pretty small minutes, which cautions against excitement, especially when you have The Real Deal Mason Mount in the mix:
People sometimes like to argue about model outputs, but I’m not interested in that here, as Mason Mount is constantly selected and great. In ways he reminds me of Italian midfielders of the late 1990s, an Angelo Di Livio or Massimo Ambrosini or Alessio Tacchinardi, players that were surrounded by flair and technical brilliance yet absolute team soldiers and vital cogs. That possibly denigrates everyone I’m talking about here, particularly Mount, who can contribute well at the business end of the pitch too, yet it’s really not meant to, Mount himself has had to semi-justify his position in the Chelsea and England team for the best part of two years, but Lampard knew his worth, and perhaps saw something of himself in him, succeeding through will and graft where more naturally gifted rivals faltered. He started him in 49/57 league games for Chelsea and only missed pitch time in two. Tuchel is under no illusions either, in May saying “He is crucial for our game, he is an absolutely key player” and the fans voted him Chelsea Player of the Year last season. And he’s still just 22! Unfortunately fellow midfield man Jorginho took the Champions League / Euros double, to hit his own high note, but let’s move beyond that for now and celebrate Mount, who also successfully boosted all of his expected metrics moving from Lampard’s team to Tuchel: Sorry, a sideline. So what did Tuchel do? We established that the defence improved, and it did so in the most desirable way: they reduced the volume of shots they were giving up and the shots they did give up were harder to score than the ones they had been giving up before, magic! Check out the annotation, one shot! For the record a Christian Benteke header, you can maybe understand how the scout report may have missed on that as Benteke’s long game of undershooting xG for multiple seasons paid off with decent goal returns in 2020-21. Overall, reducing the volume and quantity of shots allowed came across all facets of the game. They halved the volume of “clear” (just the keeper to beat) shots they allowed, reduced opposition set piece effectiveness and gave up fewer counter attacking shots. Part of how they got there was that Chelsea upped their tempo out of possession. Under Lampard they were fairly active and ranked fourth to sixth for all of PPDA (Passes Per Defensive Action), the average height of their defensive actions and their overall responsiveness to pressuring opposition ball receipts (our “aggression” metric). It took a little time under Tuchel–recall a handful of slower, possession heavy chance-lite fixtures in the early weeks–but during the second half of the season, they were second for PPDA (behind Leeds, of course), third for height of defensive actions (behind Man City and a resurgent Liverpool) and second for aggression (behind Leeds again), all notable moves in a more active direction. Just for raw pressure events and defensive actions, the workload went up, up, up before coming down, down, down just as they were all in on the Champions League, but we can see here more events, and a higher proportion of pressure events as Tuchel’s tenure settled in. They have the makings to play this way now and be effective with it: Some of the methodology also involved
ball-hogging dominating possession: they played more passes than Manchester City in their 2-1 win and routinely outpassed weaker teams by large volumes. But they could win in other ways too, as a 1-0 victory over Liverpool showed. They played a fairly rigid and deep 3-4-[big gap]-3 and outworked their opponents while giving up next to nothing shot (7) or xG (0.28) wise. On the largest stage, the Champions League final was not dissimilar. How do you improve a Champions League winning team that has shown it can outwork, out pass, out shoot and out defend its opponents, seemingly at will? Chelsea are eternally in “win-now” mode and “win-now” mode means buying Serie A’s best striker for close to £100m to End Instantly debates around how you can man your front three, whether a false 9 will work best or if your very-good-but-to-my-mind-not-quite-good-enough-to-lead-a-Chelsea-front-line-perhaps-a-tier-lower-23-year-old-academy-graduate is the right choice. And why have they done this? Finishing. The divergence between Chelsea’s stellar Tuchel era metrics and the reality of clambering into the top four slots can be blamed on one thing: the attack fired well under expected values under Tuchel. Analytics 101 remains get the process right and let the variance work itself out. In truth this was a team effort. Thirteen Chelsea players took ten or more shots in the Premier League under Tuchel and of those thirteen, a meagre two of them exceeded their goal expectation: Kurt Zouma (one goal from 13 shots and 0.85 xG) and Marcos Alonso (two goals from 20 shots and 1.62 xG). This is frankly ridiculous, and not really a reflection of the quality of Chelsea’s players. Werner and Havertz may have had personally less impressive seasons than they may have hoped but they’re not obviously sub-par finishers, nor historically was Olivier Giroud. One specific aspect of play they did not get from their forward corps was as follows: Yes; a guy crashing the six yard box. It’s not that Lukaku is a noted plus finisher, more that he is a reliable scorer–he will take up the positions you need from your main striker and score goals. To this regard Lukaku does have the vibe of a missing piece and seven years on from departing for a decent fee is returning. It will be hoped that as a focal point, Lukaku can enable his equally talented colleagues to thrive around him, and regardless he’s surely as close to guaranteed as any Chelsea striker to chip in handily. More broadly on personnel, while clued up fans may bemoan the loss of Abraham and Fikayo Tomori, they’re getting very good fees for these players and the supply line from their youth teams to the first team is doing just great, with Mount, Christensen and James all hitting big recently. Projection There’s a disconnect between stellar Tuchel-era metrics and winning the Champions League contrasting with 2020-21 points accrual (76 point pace) and bookmaker expectations (around 76-78 points). This plants Chelsea firmly alongside Liverpool in a “best-of-the-rest” category, a couple of clips ahead of Manchester United yet trailing Manchester City. In real terms they will likely need to bounce forward another ten points on top of that and make a +20 points season jump to season to contend for the title. With a summer of planning for Tuchel, a stable squad that isn’t undergoing much remedial work and the natural belief of a successful team, it’s possibly easier imagining Chelsea steering upwards once more than not. With Pep Guardiola, Jürgen Klopp and now Tuchel in the Premier League mix, it would be thrilling to see these three teams battling hard on all fronts and this season is well set for these coaching titans to tee off. Evidently Tuchel has not found long term stability in his managerial career, but with this squad and the big prize already in his back pocket, he may be primed to stay a good while yet. The league is better for that.
Want to read about another team? The rest of our Premier League season previews can be found here If you’re a club, media or gambling entity and want to know more about what StatsBomb can do for you, please contact us at Sales@StatsBomb.com We also provide education in this area, so if this taste of football analytics sparked interest, check out our Introduction to Football Analytics course Follow us on Twitter in English and Spanish and also on LinkedIn