The scale of Liverpool's challenge in appointing their next manager cannot be underestimated.
Liverpool's hierarchy understand to the highest degree that there isn't another Jurgen Klopp out there. They are not interested in a 'lite' version of him either; someone who can almost play the same way, someone who can kind of develop talent well, someone the raw data says is the closest thing.
Liverpool know that appointing a new manager - the right fit for the future - is not a search for Klopp 2.0. That would be a wasted, failed, frankly ridiculous task.
But they are also aware that whoever succeeds the German needs to connect with the supporters, the city, and the spirit of the club. As one former member of staff, who worked closely with Klopp and was privy to databases of analysis, put it: "There are a lot of good managers out there. There are not a lot of good Liverpool managers."
So, how does the club filter their search for a successor? There have been accurate reports that a data-driven approach will be used by Liverpool, but that has been misread as locating a statistical match in terms of playing style and formation used.
While underlying numbers - such as measuring overperformance and impact on a club - will guide the process, it will not decide it. Liverpool have to look beyond the data and seek out someone the squad, staff, and supporters want to invest in and join on a fresh journey.
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But one reason why Liverpool's challenge is so seismic is because Klopp was determined that his own journey with the club wouldn't end when he disembarked.
It was the summer of 2016, in a secluded terrace at the Four Seasons hotel in East Palo Alto, where Klopp revealed he was already mentally sketching what he'd want Liverpool to look and feel like when he left the club.
It was the manager's first pre-season in charge having been appointed in October, and midway through discussing pressing triggers and the importance of midfielders understanding orientation, he stopped. The conversation was too focused on the present, on tactical details, on how to get results.
"In football, it's always about pressure and the next game, next game, next game," Klopp told this writer in an exclusive interview.
"When you sit in the main chair like I sit, you have a lot of power, but even more than that, you have all the responsibility.
"And responsibility for me means it never ends, even when you leave. You need to create something where you can really be measured by, even after you've gone.
"Build this, improve that. I'm interested in everything, in the whole club and when I leave at some point, I don't want people to celebrate me still, I only want that they can still feel the benefit of me being manager here."
In three months' time when Klopp bids an emotionally charged goodbye to Liverpool, there will be endless column inches, TV segments, audio hours, and a sea of social media posts attempting to measure his legacy.
None will fully be able to capture it because Fenway Sports Group didn't just hire an elite, transformational manager, they got a guy who, well… got it. Someone who genuinely cares about the health of the club, the heartbeat of the fanbase, the soul of the place, and is invested in the harmony of pulling everything and everyone together in a shared experience.
Football has never been purely transactional for Klopp; not a scoreline nor a sequence of 90-minute battles throughout a season. It's not even about silverware. "I know football is about success," he explained, "but it's also worth having a situation in 20 years when you can look back and think over the great times you had together in this development."
FSG president Mike Gordon's framing of Klopp as one of the ownership's "greatest blessings" following the announcement that he would be exiting the club at the end of the season spoke volumes. So too the emphasis that they are "hugely saddened to lose not just a manager of such calibre, but a person and leader for whom we have enormous respect, gratitude and affection."
But an almighty task is further complicated by the absence of a sporting director. FSG failed in their bid to bring Michael Edwards back to the club in a role with wider scope to lead the restructure at Liverpool.
The club know synergy between a sporting director and manager is crucial not just for success, but a happy football environment.
Gordon is overseeing the process for both major hires, armed with information from the research department led by Will Spearman.
Liverpool, by habit, continuously assess emerging managers alongside players.
Extensive dossiers - the one on Klopp in 2015 contained 60 pages - on potential candidates to succeed the German will already be drafted.
Having taken a deep dive through data and assessed the careers of some of the names that could be the frame, Xabi Alonso, the Bayer Leverkusen manager, shines as the stellar option. Klopp himself has labelled the 42-year-old the "standout" among the next generation in the dugout.
Sky Sports News presents our findings on Alonso, Roberto De Zerbi, Thomas Frank, Ange Postecoglou, Julian Nagelsmann, Ruben Amorim and Francesco Farioli.
Xabi Alonso
It is testament not only to his suitability for the role, but his status as the next top manager that Alonso is spoken about separately in the discussion for the Liverpool job. There is Xabi, and then The Others.
It is a consequence of his small yet sublime body of work so far; the construction at Real Sociedad B, leading them back to the Segunda Division for the first time since 1961-62 and then quickly transforming Bayer Leverkusen into a tactically supreme unbeaten machine.
Only Pep Guardiola's Bayern Munich have ever set a better pace atop the Bundesliga. Bayer have not been beaten in 32 matches across all competitions, are in the German Cup semi-finals, and the last 16 of the Europa League. They are on a special run and are primed to make history this season.
Bayer play with panache and intelligence; lionising possession but also shifting to control the game without the ball as they showcased in a 3-0 masterclass against Bayern.
There have been attempts to suggest Alonso's approach jars with the more direct and transitional qualities of Liverpool's squad. While Bayer do employ a more patient build-up that is comparable to Manchester City, his Real Sociedad B were much less geared to short passing. Alonso has illustrated his adaptability already between those clubs, but also against different opponents.
His unexpected selection against Bayern and switch to an off-the-ball focus to nullify Thomas Tuchel's side was a great example.
Granit Xhaka flagged Alonso's flexibility within his principles. "Mikel [Arteta] for example, he has his philosophy and that's it," he said.
"Even to play always with a back four and never change to a back five for example, or never change like a 4-4-2 with two proper strikers. So you had this 4-3-3, with one six and two eights.
"Xabi is a little bit different. I think that Xabi can play a back four, but he can play as well a back five, you know?"
Leverkusen's high press is more effective than Liverpool's and they average 1.2 fast breaks per game, which is almost double the corresponding figure for Klopp's men.
Defender Jonathan Tah has raved about Alonso's ability to clearly communicate his demands, and the balance between repetitions in training sessions to nail sequences and the personality of the manager, which generates the buy-in and faith in his methods.
Bayer's sporting director Simon Rolfes, says the club have adopted "a seriousness and maturity which reflects Xabi as a person". Tactically, and as a figure to represent a club, Alonso is already showing elite attributes.
He already feels like a Liverpool manager, and that's without factoring in his understanding of, and bond with the club developed during five seasons of setting the tempo in their midfield.
Alonso fits the dynamic of an exciting, young team heaving with potential that will need some nips, tucks and to create a new story.
There are complexities; he is still early into his Bayer project and ideally would have mapped a longer period of construction with them. Alonso's focus, rightly, is on growing a fantastic season with top honours.
The club don't want to lose him, but know he'll have his pick of options - Real Madrid and Bayern Munich will soon be knocking too - and can decide his timing.
Liverpool would not want to do anything to disrupt Alonso's current work. He is worth the patience though, and doing whatever is necessary to get.
Roberto De Zerbi
"One of the most influential managers of the last 20 years," according to Guardiola, and a man who is on City's list to one day succeed their phenomenal tactician. De Zerbi's ability to innovate and communicate unique concepts to his players, who absorb it so quickly and effectively, is a core weapon.
Adam Lallana talks about how the Italian "made football make so much more sense to me," while Lewis Dunk offered: "I see football in a completely different way since the new manager has come in. The idea of what I did before, I thought it made sense. But when you learn something completely different, you believe in it and this makes sense. You think: Why didn't I know this?"
De Zerbi's passionate and emotive personality resonates well with players, with the ones he coached at Sassuolo and Shakhtar Donetsk still remaining in regular touch with him. It is unequivocal that he makes individuals and teams much better, convincing them that there is no limit to what they can achieve.
And so, the team with the estimated second-lowest wage bill for last season plays with the same kind of ball monopolisation as the all-conquering, state-powered, treble-winning City.
Only the champions have more possession than Brighton and sequences with 10 or more passes. They use the ball differently though and press higher and more intensely with more switches of speed to their game.
While Brighton largely are a contrast to Liverpool's directness, Alexis Mac Allister, Lallana and James Milner will provide testimony that De Zerbi can fuse the Merseysiders' dynamism with more control.
There will be question marks over defensive numbers and how his temperament would stack up in a more pressured, demanding environment, but the 44-year-old ticks a lot of the main boxes.
He outperforms resources, has a magnetic personality, plays the kind of football that draws applause from other managers and improves players.
Thomas Frank
If you were looking for a statistical match for Liverpool's approach, the data would highlight Frank's Brentford, who are as direct, play with similar speed and intensity, and switch the play nearly as much.
The Dane is a very good coach, proving he can toggle between building an attacking machine to tear through the Championship and a more defensive-minded, effective unit to consolidate Premier League status.
Frank communicates well, with his open and honest nature appreciated by owners and senior executives who have to consider how their club is represented in front of the cameras every few days.
The relationship he has built with Brentford fans is another big nod, as is his improvement of players like Ivan Toney, David Raya and Ezri Konsa.
Frank fairs highly in terms of maximising resources and going beyond expectations. The big unknown is how he would cope out of Brentford's super slick, controlled operation and if he can transition to a club that wants to be a domestic and European powerhouse, where draws feel like defeats.
Ange Postecoglou
Had the timing been different, this would be a much more interesting discussion. Postecoglou, the manager and the man, has been admired by Liverpool for a long time and he would always show up in the research as someone worth assessing.
While his work at Tottenham has only solidified the evidence that he is a top manager with clear, progressive principles and the talent for implementing them quickly, he is… Tottenham's manager.
A scenario where Liverpool try to tempt him now feels implausible, before factoring in what Spurs' automatic stance would be.
Stylistically, under him, the pressing metrics of the north Londoners are very similar to Liverpool. They are the highest in the league for pressed sequences, with Klopp's side second. Spurs also pass forward at roughly the same rate.
Postecoglou's only huge issue is that he is already at a rival club. Liverpool's profile now also seems more geared to a younger man in the dugout.
Julian Nagelsmann
Held in high esteem for his innovation at Hoffenheim and then tactical fluidity at RB Leipzig, friction at Bayern might have affected the external perception of Nagelsmann but his reputation is still high within football - particularly given Tuchel's struggles there.
On a short contract with the German FA that runs through the Euros, the 36-year-old - who turned down Real Madrid five years ago - is built to manage in the Premier League.
He declined opportunities at Chelsea and Tottenham last year and for a long period, it had felt like he was positioning himself to succeed Klopp; down to sharing an agent in Marc Kosicke.
That representation changed prior to Nagelsmann joining Bayern and he has been talked about at Manchester United in recent years more than at Liverpool.
Erroneously cast as a 'laptop coach,' he has a vibrant personality and is both articulate and engaging.
Whether Liverpool fans would warm to him is another matter, with a section still annoyed by his behaviour at Anfield for a Champions League qualifier in August 2017.
He is brilliant, with an impressive CV but it is not an automatic sell to a fanbase that needs to be enthralled by their manager.
Ruben Amorim and Francesco Farioli
Two managers who seem destined for Premier League jobs in the near future.
Amorim's transformation at Sporting is well known, where he lead them to a first league title in 19 years. They are fast, direct with high press metrics that mirror Liverpool's.
Farioli, 34, has Nice second in Ligue 1 despite operating with the eighth-highest wage bill. He was De Zerbi's goalkeeping coach at Benevento and Sassuolo but has carved a path for himself with impressive 'punching above their weight' work at Alanyaspor and Nice.
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