branislav ivanovic , john terry , gary cahill and cesar azpilicueta all starred in chelsea 's 0-0 draw against arsenal at the emirates stadium .
chelsea have conceded only 26 goals this season .
they are closing in on another premier league title under jose mourinho .
chelsea 's defence have proved that a solid back four is key to a charge .
jamie carragher : terry is the premier league 's greatest ever defender .
terry on course to take part in all pl games for first time in his career .