Whether some fans like to admit it or not, transfers play an important role in a football team’s success, and it’s no different in the Premier League.

While Manchester United fans will always look fondly on the Class of ’92 and the success it brought them, other clubs have used the transfer window to bolster their squads.

In 2020, it’s a tactic Chelsea are currently employing, looking to improve on their fourth-placed finish in 2019/20. The Blues have already signed Hakim Ziyech, Timo Werner, Thiago Silva, Ben Chilwell and Malang Sarr, and appear to be close to signing Kai Havertz. Some have already made the bold claim that Chelsea are having the best transfer window in recent memory.

However, big signings, or busy transfer windows don’t always work out. For every success story, there’s a Tottenham in 2013/14 or Fulham in 2018/19 where a mass overhaul just doesn’t cut the mustard. But we’re not here to focus on those, we’re here for the positivity.

Looking back over every season in the Premier League, we’ve picked out what we believe are the 10 best transfer windows in the competition’s history – based on the business done and the subsequent impact on the club in question, not just for the season but also in the long-term.

Now, transfer windows were only introduced in 2002/03 so for seasons before then, business over the whole year is taken into account. But after 2002/03 we are just looking at sole windows, meaning teams that had good deals in both the summer and winter may be lower down or out of the top 10 entirely. And for teams that had more than one good transfer window in close proximity – Chelsea at the start of the Roman Abramovich era, for example – we’ve picked out a single window, that we felt was most important.

That’s all the technicalities over, so let’s get onto the list shall we?

Disagree with any of our picks? Let us know on Twitter or Facebook!

10. Arsenal (2001/02)

Notable signings: Giovanni van Bronckhorst, Edu, Kolo Toure, Sol Campbell.

Arsenal aren’t really one of those clubs that will look to build a new team in one window, and the late 1990s and early 2000s are prime example of that with the likes of Dennis Bergkamp, Thierry Henry, Emmanuel Petit and Marc Overmars all being brought in over various campaigns.

But in 2001/02, the final season before fixed transfer windows would come in, the Gunners put the finishing touches on the squad they had been building with big signings. The biggest name at the time was Giovanni van Bronckhorst, signed from Rangers, but no player had a bigger impact than Sol Campbell who joined for free from rivals Tottenham.

Also signing Edu and Kolo Toure, Arsenal won the Premier League and FA Cup double that season, but the impact of the transfer window was slightly more lasting. Both Toure and Campbell were part of the Arsenal team that looked to dominate England, winning the Premier League without losing in 2003/04 as well as two more FA Cups. This is only as low as it is because the bigger business had been smartly scattered over previous years.

9. Liverpool (1999/00)

Notable signings: Emile Heskey, Dietmar Hamann, Vladimir Smicer, Sander Westerveld, Stephane Henchoz, Titi Camara, Sami Hyypia

Once kings of England, Liverpool were going through a period of uncertainty in the late 1990s and early 2000s, having to watch on as rivals Manchester United closed the gap on their league title record. But in 1999/2000 they looked to remedy that.

Across the season, the Reds brought in key players at various positions, from forward Emile Heskey to defender Sami Hyypia and goalkeeper Sander Westerveld. Now, not every player was a success, but those that were, secured a place in club history. The following season saw Liverpool win a treble, consisting of the FA Cup, League Cup and Uefa Cup, while the Reds also climbed to fourth in the Premier League having finished seventh in 1998/1999.

For some that might have been enough, but Hamann, Smicer and Hyypia were all still a big part of the Liverpool side that won the club’s fifth Champions League title in 2005, starting in the final. Hamann scored in the shootout while Smicer both grabbed Liverpool‘s second goal of the night and scored a crucial penalty.

8. Chelsea (Summer 2014/15)

Notable signings: Diego Costa, Cesc Fabregas, Filipe Luis, Loic Remy, Didier Drogba.

The second coming of Jose Mourinho at Chelsea brought a big summer transfer window in 2014/15, with Diego Costa and Cesc Fabregas making their way to Stamford Bridge alongside Filipe Luis, Loic Remy and Didier Drogba.

Although Luis and Remy did not have the impact they would have liked, and Drogba was signed more for his experience, Costa and Fabregas changed the game for Chelsea. A team that had looked toothless in May 2014 was cutting through opposition defences by August, largely thanks to the partnership between Costa and Fabregas. Costa scored 20 goals and Fabregas recorded 18 assists as the Blues won the Premier League at a canter. The duo would combine again for another title in 2017 under Antonio Conte.

What stops them from being higher are a few things. Firstly, the Blues had been silently building over the previous years with Eden Hazard, Oscar and Cesar Azpilicueta already at Stamford Bridge. Costa’s impact was often reserved for the first half of the season, scoring the majority of his goals before Christmas. And then there was the nightmare 2015/16 campaign. It was all just a bit too short-lived.

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7. Blackburn Rovers (1992/93)

Notable signings: Alan Shearer, Stuart Ripley, Graeme Le Saux, Tim Sherwood, Henning Berg.

Before Chelsea and Manchester City were being accused of buying the Premier League, it was Blackburn who fans pointed the finger at. But the club has to be commended for the business they completed in the very first season of the newly-revamped top flight.

Rovers wasted little time in improving their squad, signing Alan Shearer from Southampton in the summer, while also adding Tim Sherwood and later Graeme Le Saux – among many others. It wouldn’t be an immediate success, with Manchester United winning the first two Premier League titles, but Blackburn’s time finally came in 1994/95. Led by captain Sherwood, Blackburn won their third league title, with Shearer top-scoring on 34 goals for the season. Blackburn wouldn’t win another league title, and Shearer eventually left, but what a campaign for the Lancashire outfit.

6. Manchester United (Winter 2005/06)

Notable signings: Nemanja Vidic, Patrice Evra

Like Arsenal, Manchester United have often been smart with their signings, adding big names over a long period of time – years rather than one window. But arguably the best single window the Red Devils have overseen was the winter of 2005/06.

Having to watch on as Chelsea were storming their way to another title, and without one of their own since 2003, Man Utd decided January 2006 was the time to bolster their defence. In came Nemanja Vidic and Patrice Evra and though Chelsea did win the league in 2005/06, Man Utd were set. The Red Devils, with Vidic and Evra at the heart of their defence, won the next four of the next five Premier League titles, not to mention the Champions League in 2008. When they eventually left United, Vidic and Evra had written their names in the Premier League history books as two of the competition’s best ever defenders.

Man Utd would have been higher if we were taking a whole season into account post-2002, with the Red Devils signing Edwin van der Sar and Ji-Sung Park in the summer of 2005 – or calendar years with Michael Carrick coming in the summer of 2006.

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5. Liverpool (Summer 2018/19)

Notable signings: Alisson, Naby Keita, Fabinho, Xherdan Shaqiri

A second Liverpool transfer window in the top 10, the Reds used the summer 2018 slot to put some big finishing touches on their squad. Having just lost the 2018 Champions League final to Real Madrid, with a lot of negative attention being placed on Loris Karius, Liverpool brought Alisson in from Roma to become the new number one. Fabinho and Xherdan Shaqiri also signed, while Naby Keita joined with a deal being agreed the previous year.

The impact was almost immediate. Liverpool lost just one Premier League and missed out on the title by a point, but they did claim their sixth Champions League trophy thanks to a 2-0 win over Tottenham Hotspur. Then, a year later, Liverpool had one of the most dominating title wins in Premier League history, essentially wrapping up the league by the start of March – though it wasn’t confirmed until July – with Alisson and Fabinho key.

A large part of Liverpool’s title-winning squad having been signed in the windows before, including Virgil van Dijk in January 2018 and Mohamed Salah in the summer of 2017, is what is currently keeping the Reds in fifth place. But if they do build on the title win and dominate the Premier League with Alisson and Fabinho, they will have every chance of climbing even higher.

4. Manchester City (Summer 2015/16)

Notable signings: Kevin De Bruyne, Raheem Sterling, Nicolas Otamendi, Fabian Delph

In the summer of 2015, Manchester City were left somewhat licking their wounds having finished eight points behind Premier League winners Chelsea. The Citizens had previously won the league in 2012 and 2014, so were looking to get back to winning ways with the signings of Kevin De Bruyne, Raheem Sterling, Nicolas Otamendi and Fabian Delph.

The immediate result was bad, with City finishing fourth and only securing a place in the Champions League on goal difference. But once Pep Guardiola came in the following summer, the quartet signed in 2015 all shone. De Bruyne is now the best player in the Premier League and an assist fiend, while Sterling has added goals to his game, often proving a frightening opponent in front of goal. The pair, alongside Otamendi and Delph – who found a spot at left-back under Guardiola – helped City win back-to-back Premier League titles, recording 198 points across the 2017/18 and 2018/19 campaigns.

But the fact they needed more signings and a new manager to get to that success, is what slightly holds the window of 2015/16 back.

3. Leicester City (Summer 2015/16)

Notable signings: Shinji Okazaki, N’Golo Kante, Gokhan Inler, Robert Huth, Christian Fuchs.

No big money signings, relatively unknown names brought in, but what a transfer window Leicester City had in the summer of 2015/16. Leicester’s aim in the window would have been to add to a squad that had narrowly avoided relegation, looking to make safety a bit easier to achieve the following campaign. What happened, was remarkable.

Okazaki, Kante, Huth and Fuchs were all absolutely vital to Leicester shocking everyone in football – and even those who don’t care about it – by winning the 2015/16 Premier League title. Kante was understatedly excellent, playing 37 games of the season, Huth played 35, Fuchs 32 and Okazaki 36, scoring five goals. That Kante won the Premier League the following season after joining Chelsea was telling as how much of a gem Leicester unearthed.

The only thing keeping Leicester from arguably having the best transfer window in Premier League history is a lack of longevity (in part due to their best players being tempted away), which leads us onto the final two.

2. Manchester City (Summer 2010/11)

Notable signings: Yaya Toure, Mario Balotelli, David Silva, Aleksandar Kolarov, Jerome Boateng.

People will perhaps point to the 2011/12 season for Man City, with Sergio Aguero signing and the Premier League title arriving at the Etihad. But this was Man City’s window. Just look at those names. Yaya Toure and David Silva, who have both gone down as two of the best players in the club’s history, the latter earning himself a statue outside the Etihad.

But let’s not do Mario Balotelli a disservice. There is no Aguero moment without the Italian, who recorded his only Premier League assist in setting up the title win. Or Aleksandar Kolarov, remembered fondly for bombing down the flank with his rocket of a left foot, attacking more than some of the wingers in his team.

Toure, Silva and Kolarov all remained for the 2014 title win and laid down the foundations for Man City’s growth.

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1. Chelsea (Summer 2004/05)

Notable signings: Didier Drogba, Ricardo Carvalho, Paulo Ferreira, Arjen Robben, Tiago, Petr Cech, Mateja Kezman.

The benchmark, however, remains Chelsea’s transformative summer of 2004. The changes may have started in 2003 with the takeover by Abramovich and some important signings being made, but the following year was on a completely different level.

Backed by Abramovich, Chelsea spent big on Didier Drogba, Ricardo Carvalho, Paulo Ferreira, Arjen Robben, Tiago and Petr Cech – though the deal for the latter was technically agreed before the summer. These were statement signings, showing Chelsea meant business, and it paid off. Their first season at Chelsea ended in success with the Premier League and League Cup, followed by another league title.

As the years went on, some players left, including Robben, Tiago and Mateja Kezman but the rest remained for two more FA Cups and a Premier League – including the Double. Then Drogba, Cech and Ferreira were all part of the Chelsea squad that won the Champions League in 2012, with the former two becoming the heroes of the night – almost eight years after initially moving to west London.

There has not been a more important, or better, transfer window by a single club in Premier League history and it will take some beating.

Honourable mentions: Newcastle (1995/96), Manchester United (1998/99), Portsmouth (Summer 2007/08), Southampton (Summer 2014/15), Wolverhampton Wanderers (Summer 2018/19)