are a club that notoriously spends a lot of money on recruiting players with mixed results over the years. Ever since Russian billionaire Roman Abramovich purchased the club in 2003, the Blues have ranked as one of the richest football clubs in the world and have invested heavily in their quest to attain domestic and European glory. How the club have gone through managers over the years has made it difficult for a specific style of play to be established at the club.
This has had the knock-on effect of players being bought to play a certain way under one manager which renders them less useful in a new manager's system. In summary, Chelsea have made a lot of signings over the years which have not worked out. However, there have been windows throughout the era where they have got it right and the players signed have gone on to have long, successful careers at Stamford Bridge.
Here is a ranking of the club's ten best transfer windows of the Premier League era - the transfer window was only introduced as a concept to the division in 2002, so no bits of business before that, such as the purchase of Gianfranco Zola or Frank Lampard, will be included. This list has been compiled based on several factors: Some signings on this list were great for the immediate future, but may not have been the best investment and meant the club only got a few years out of them before they were shipped out at a loss. There have been several occasions where Chelsea have definitely sold a player too soo.
