Chelsea's Oscar, second left, celebrates scoring his hat-trick goal with, from left, Nemanja Matic, Eden Hazard and Branislav Ivanovic during the English FA Cup fourth round soccer match between Milton Keynes Dons and Chelsea at Stadium mk in Milton Keynes, England, Sunday, Jan. 31, 2016. (AP Photo/Kirsty Wigglesworth)
Chelsea's Oscar, second left, celebrates scoring his hat-trick goal with, from left, Nemanja Matic, Eden Hazard and Branislav Ivanovic during the English FA Cup fourth round soccer match between MiltoShow more
The Guus Hiddink effect: Chelsea smiling again after Oscar hat-trick in FA Cup
Against MK Dons, Chelsea played with confidence and conviction. They lost their way, their authority and their identity in autumn. They have regained purpose and freedom, which can seem incompatible, writes Richard Jolly.