As Tottenham Hotspur prepare to join the ranks of clubs making record-breaking transfer window outlays, we take a closer look at the current top 10 biggest single-window spends in football history and assess how those investments fared.

While heavy spending often raises expectations, it has rarely been a guarantee of success. Spurs supporters may want to heed the lessons from previous big-spending clubs that failed to deliver on the pitch despite their lavish investments.

Here are the 10 largest single-window spends by a football club, ranked by how successful those windows ultimately proved to be.

During the first major transfer window under the BlueCo ownership, Chelsea seemed to adopt a policy of signing any player available. The London club brought in eight permanent new signings and one on loan, with Wesley Fofana being the costliest at £70 million and a £200,000-a-week wage on a seven-year contract. However, given his recurring injury problems, there is already speculation about his potential departure this summer.

Raheem Sterling’s arrival from Manchester City initially looked promising, but his form declined sharply soon after. Marc Cucurella turned out to be the standout signing, recovering from a poor start to become a key player for Chelsea and later earning the club a profit through his sale to Real Madrid. Conversely, Kalidou Koulibaly and Pierre-Emerick Aubameyang were unmitigated disappointments.

Had this been a summer window, Chelsea might not have made the list, but inflated winter market prices saw them pay excessive sums for largely average talent. Enzo Fernandez, though a quality player, raised questions about his £106 million price tag. Malo Gusto has been solid, but Benoit Badiashile has not justified his fee. Mykhailo Mudryk’s £88.5 million move proved disastrous, as he was later banned for doping – and even before that, he looked an expensive mistake. Chelsea also paid a £10 million loan fee for Joao Felix, who was sent off in his debut match.

Chelsea’s subsequent summer spree did not deliver much better results. Joao Pedro, the most expensive addition, scored 15 goals in his debut campaign, while Estevao and Jorrel Hato showed promise for the future. On the downside, Liam Delap and Jamie Gittens struggled badly, with Gittens’ signing raising eyebrows given the club’s existing surplus of wingers. Alejandro Garnacho’s £40 million move also looks regrettable, with reports suggesting Chelsea might sell him for half that figure.

Saudi club Al-Hilal’s £77.6 million capture of Neymar was another example of big spending gone wrong. His persistent injuries meant the club effectively paid around £37 million per appearance and £610,000 per minute of play. Despite that, Al-Hilal still enjoyed a record-breaking season with 32 consecutive wins and a league and cup double. They also added Malcom, Sergej Milinkovic-Savic, Ruben Neves, and Aleksandar Mitrovic – all players in their prime.

Real Madrid’s 2019 splurge focused on Eden Hazard, but the Belgian never recaptured his Chelsea form. Injuries derailed his time at the Bernabéu, and he never managed more than three La Liga goals in a season. Luka Jovic was also a disappointment and quickly sent out on loan, while Rodrygo, Eder Militao, and Ferland Mendy proved to be far more effective acquisitions.

Barcelona’s return to pursue Antoine Griezmann after being rejected the previous year turned out to be ill-judged. Though immensely talented, the Frenchman operated in similar areas to Lionel Messi, leaving him without a clear role in the team. Despite 35 goals and 17 assists in 102 matches, he never replicated his Atlético Madrid brilliance. The €75 million spent on Frenkie de Jong also looked questionable at first as the club tried to offload him in later years, though he has since become central to Hansi Flick’s plans. The signing of 16-year-old Pedri from Las Palmas, however, has turned out to be one of the best pieces of business in recent memory, even if most of the other arrivals failed to impress.

Liverpool’s recent summer recruitment remains under scrutiny, with only a year gone by and early signs being mixed. Florian Wirtz has struggled to adapt to the Premier League, contributing just nine league goals. Alexander Isak’s leg fracture has left doubts about his recovery, while Milos Kerkez underperformed and Jeremie Frimpong failed to find his best role. Hugo Ekitike was the only unqualified success story of that window.

Chelsea’s 2023/24 summer window featured both standout successes and expensive disappointments. On the positive side, Moises Caicedo and Cole Palmer were strong additions, with Palmer going on to win the PFA Young Player of the Season award. While Palmer’s form has since dipped, Caicedo continues to excel, and Romeo Lavia could still justify his signing if he overcomes his injuries. In contrast, Christopher Nkunku and Nicolas Jackson, who cost a combined £84 million, both spent last season away from the club. Goalkeeper Robert Sanchez also arrived that summer and continues to divide opinion.

Paris Saint-Germain’s window can be considered a success, largely because one of their signings went on to win the Ballon d’Or. Interestingly, Ousmane Dembele was not the priciest addition, as Randal Kolo Muani and Manuel Ugarte commanded higher fees, but Dembele became a cornerstone of Luis Enrique’s setup. Bradley Barcola impressed at the World Cup but has yet to establish himself at PSG, while Lucas Hernandez was another astute acquisition. PSG also signed Hugo Ekitike, taking a small loss on him later, and cleverly activated a buy-back clause for Xavi Simons, later selling him for a €44 million profit.

Arsenal’s transfer window aimed at pushing them over the line for the Premier League title and fully succeeded. Viktor Gyokeres may not have been the definitive answer up front, but his arrival, alongside Martin Zubimendi, Eberechi Eze, Noni Madueke, and Cristhian Mosquera, gave the Gunners the squad depth they had long lacked. While only Zubimendi became a regular starter, all contributed meaningfully to Arsenal’s title-winning campaign. Every rupee spent was justified.