Playing 3 at the back against Leicester has been so blatantly obvious for months now. Two strikers against 3 defenders. So many teams went 2v2 in that area which shows how poor tactically a lot of managers in this league are.
Leicester's defence is very one dimensional and any little flicks or passes in behind causes them huge problems. This is a clear tactic of Chelsea and they've done it really well so far, especially Costa & Hazard.
Leicester's centre midfield has nowhere near the energy required for a midfield two.
David Luiz has been excellent so far in a sweeper role, his distribution is up there with the best CBs.