Despite what the record books say, it wasn't always plain sailing at Manchester United under Sir Alex Ferguson.
They ruled the Premier League during the Scot's tenure, but had periods where they had to accept they were second best. Arsenal had their moments in the sun, Chelsea looked unstoppable for several seasons when the Roman Abramovich billions and Jose Mourinho arrived.
United though kept coming back - time and time again. Ferguson was able to rebuild his squads, adding quality annually, bringing through young talent along the way. It meant the United stayed very much relevant and, more importantly, competitive.
That is the task now facing Jurgen Klopp - one that doesn't often present itself to the modern day manager. The eras of having a manager for decades have gone, a four-year spell at a club is considered relatively long. It means the ability to rebuild and deal with transition periods isn't as vital as it once was.
Klopp took charge in last 2015 and this is his seventh full campaign in charge at Anfield. He built steadily before realising the squad's potential with a Champions League win in 2019. The Premier League followed 12 months later. Now though, there is concern on Merseyside.
Many of the stalwarts who experienced success are still the main men now. Much has been made about the lack of investment in what is now an ageing midfield. The back four, whilst brilliant, has remained similar throughout. The forward ranks have changed, but the barometer remains the trio of Roberto Firmino, Sadio Mane and Mo Salah.
Ferguson showed himself capable, on numerous occasions, of moving big names and big players on if it benefitted the team. Some of those were as a result of off-pitch issues, but the Scot was willing to take a long-term perspective when required.
Back in 2002, a decade after he first delivered a league title to Old Trafford, he said: "We have created three teams in 10 years here, and it is possible we are on the way to building another one. And if we do, obviously new players can come in.
"We have trusted and believed in the nucleus of our squad, which has been there for a long time. We always try to improve, and we have done that each summer, or we try to sign at least one player. Maybe it is time to assess that the nucleus of the team has been together for seven to nine years - it's a long time."
An era that began with the likes of Paul Ince and Steve Bruce as key figures transitioned into one dominated by Roy Keane and the Class of 92. Stardust was added in the form of Cristiano Ronaldo, Wayne Rooney and Carlos Tevez - who would go on to form the finest attack of Ferguson's era.
They helped deliver the 2008 Champions League - nine years are the famous treble winners had done the same. By the time Ferguson called time on his career he'd seen Robin van Persie power United to, yet another, league title.
Klopp has managed to accomplish things Ferguson didn't. The German's highest points tally at Anfield - 99 - dwarfs the Scot's best effort in a 38-game season. Ferguson's greatest accomplishment though was the ability to go again and again.
Liverpool must consider their contingency plans. What happens when Alisson is no longer considered among the best goalkeepers in the world? How long will Virgil van Dijk's peak last and where will the goals come from when Mohamed Salah goes.
The Reds must be proactive, not reactive, if they are to challenge the likes of Manchester City consistently. Whilst the likes of Ibrahima Konate and Darwin Nunez have been added to address problem areas, the jury is still out and Liverpool have been unable to add them into a winning outfit, rather one that is copping regular criticism.
Central midfield remains a major area of concern and failing to adequately address it has left Liverpool facing the possibility of a year without Champions League football. Ferguson showed a willingness and ability to reinvent himself - Klopp must now do the same.
