i think possesion football is not about the formation cause now every body wanna be barca lol doesnt matter the formation you play its down to the tempo you wanna play for 90mns and what you want your winger to do when they have the ball , you should have minimum 3 midfield players an anchor man that support the defence and get short passes only.for my part is slow tempo , + overlap , no long shots , and passes to fit for all but iniesta since he is the man to unlock dead situation sane when i play cesc.