why should back capping work in attack and defence games? hello thats why its called being on the defence. If you are makeing the defence attack every game you should just stamp it Reinforcements mode and get on with your life.
Calling it backcapping is misleading, its not like airborne drop behind your lines and start capping your spawn.
In order to "backcap", the other side must have at least one adjacent friendly sector. A defense is more than just sitting there in one spot, you must protect your flanks as well, and if you cannot do so, then the defense has failed.