Chelsea's cash-splurging strategy has delivered success to east London since the turn of the millennium and failed in equal measure.
During the Roman Abramovic era, the Blues became title-winning titans as the arrival of Jose Mourinho saw big spending come into fruition off the field as well as domineering displays on it.
After arriving at Stamford Bridge in 2004, the special one was given a war chest of funds to splash on talent across Europe, striking gold with the acquisitions of Petr Cech, Ricardo Carvalho, Arjen Robben and Didier Drogba, in particular.
That quartet were instrumental in the Blues scooping consecutive Premier League titles in 2005 and 2006, although supporters will look back on the mid-2000s with fond memories, it's also a barometer for how far the club have fallen, especially in the transfer window.
When looking at Chelsea's recent escapades in the transfer window, it's been a while since the club has unearthed a club legend – like a Cech or Drogba – and have instead shelled out obscene amounts of cash on future flops.
The biggest of those is the £97.5m capture of Romelu Lukaku from Inter Milan in 2021, however, the signing of Kepa Arrizabalaga in 2018 has given the Belgian a good run for his money.
How much did Chelsea pay for Kepa Arrizabalaga?
When Chelsea signed Kepa Arrizabalaga for £71.6m, which still stands as a world record fee for a goalkeeper, Maurizio Sarri was sold the pipe dream of him becoming a top-drawer 'keeper who could inspire the club to a glut of title-winning campaigns.
The Spaniard arrived at the club in 2018 with big shoes to fill. He was replacing the departing Thibaut Courtois, who joined Real Madrid that summer with the tag of being world-class while Zinedine Zidane was full of adulation for the Belgian, praising him as "among the best in the world".
Courtois would live up to that praise in the Spanish capital by helping his side win two La Liga titles and one Champions League, which subsequently saw his value skyrocket to highs of €86m (£74m) in 2022, as per Football Transfers, from the initial £35m that Real shelled out for him five years ago.
Conversely, Arrizabalaga hasn't come close to eclipsing the Belgian's performances in east London and has instead drained the club financially.
From 2018 up until his departure on loan ironically, to Real Madrid in the summer, the £150k per-week dud has bled the club dry of £39m in wages alone, amounting to a staggering £110m when adding the initial transfer fee to his salary.
Transfer fee
£71.6m
Weekly salary
£150k
Yearly salary
£7.8m
Total salary
£39m
Total cost per game
£674k
Total cost per clean sheet
£1.8m
Total cost per yellow card
£11m
Data via Transfermarkt & Capology.
How has Kepa Arrizabalaga performed at Chelsea?
While Courtois reaffirmed himself as one of the best in the world at Real Madrid, Chelsea's replacement has proven to be far less successful.
The Spaniard would make a huge number of mistakes during his first few seasons at the club and when Edouard Mendy from Rennes arrived in 2020, he was relegated to second-choice.
Arrizabalaga was signed for the exceptional ability he had with the ball at his feet, but it became impossible to look past the traditional parts of his goalkeeping game when assessing his ability.
Rarely, if ever, able to make outstanding saves and simply allowing far too many shots to go past him, the Spaniard's performances were weighed down by his hefty transfer fee, making three notable errors that led to a goal in top-flight football.
In the early stages of his Blues career, the 29-year-old was subject to shaky performances and although there were improvements last term, keeping nine clean sheets in 29 appearances for a struggling Chelsea side, he still left many feeling unconvinced, including Ian Wright.
He said on the Wrighty's House Podcast: “I’m looking at Kepa and I’m sorry man but it’s not working out. The man makes too many mistakes,”
The main responsibility for any goalkeeper is to exhume confidence in between the sticks and become an imposing presence in defence, but Kepa – who was described by football pundit and personality Mark Goldbridge as "suspect" – has never really put in the consistent performances to build that level of trust.
Having kept four clean sheets in seven matches for Real Madrid so far, perhaps the world's most expensive stopper is thriving in a fresh environment, but for what he's achieved in the Blue of Chelsea, he'll still go down as one of the worst signings in the club's history.