#1 André Villas-Boas
Andre Villas-Boas was given the Chelsea job at the age of just 41. His astronomical achievement at FC Porto was enough to convince Roman Abramovich to pay the £15m compensation required to land his man in 2011. He obviously reminded Chelsea of a younger version of Jose Mourinho. However, his lack of managerial experience soon turned out to be a stumbling block in the dressing room.
The Portuguese tried to implement a new style into a team that had already won eight major trophies since Roman Abramovich's takeover. When his philosophy did not work out, he quickly lost the support of the dressing room including senior figures like Frank Lampard, John Terry, and Didier Drogba
What happened next is well documented. Roberto Di Matteo took over as interim manager in March and led the Blues to a historic first Champions League title. That victory also ensured qualification for next year's campaign, even though they finished the season outside the top four.