Cesar Azpilicueta believes a solid defence is vital to Chelsea's hopes of claiming their first Premier League title for four years.
The Blues boast the most miserly defence in the top flight having kept an impressive 14 clean sheets this season.
Jose Mourinho's side top the standings ahead of Liverpool and Manchester City with just seven matches to play.
And Spain international Azpilicueta, who has replaced Ashley Cole as the club's first-choice left-back this term, claims the players have a better understanding when they take to the field in a settled backline.
Azpilicueta told Chelsea TV: "We are defending well because everyone is defending. We are not conceding goals because everyone is doing their jobs.
"We are keeping a lot of clean sheets and why we are doing well is because of the team.
"We have very good centre-backs, quality players. John (Terry), Gary (Cahill)and David (Luiz) are very good centre-backs and the relationship between them is key for the team."