Ask nearly all Blues' fans and they will tell you that Roman Abramovich is probably the best thing that has ever happened to Chelsea Football Club.
The amount of money the Russian billionaire has invested in to the club since his takeover has been mind-blowing.
Millions have been spent on bringing the best players to West London and building the best facilities to turn the club from one that would win the odd FA Cup to a European powerhouse.
But there have been times in his nine year reign that have left Chelsea fans wondering if Abramovich is a hindrance on the club's further progress.
It is no secret that Abramovich likes to be "hands on" in his ownership and has been guilty of meddling, perhaps too much, with coaches and playing staff.
His latest managerial change has not gone down well with Chelsea fans, who are yet to warm to Rafael Benitez.
But whether this appointment was a big mistake or a stroke of genius is yet to be seen.
Here are five of Abramovich's biggest slip-ups in his time at Chelsea.