Very Basic Tactical Shape Question

[psucolonel]

Is the tactical shape you have chosen (formation) typically with possession, in transition, or without position?  So when do players fall into shape?  Obviously player instructions can make the players do different thinwhenitgs that may have them abandon (or not) their position in the formation...what is the flow of how this works?  When do players stay at home, and when might they execute an instruction that tells them to perhaps do something different?

I am a novice tactician when it comes to football, but I am still trying to learn just how things work.  Thank you for any advice and/or help.  Much appreciated.  

[HUNT3R]

You'll often hear that it's the defensive positioning, which isn't quite correct. Technically speaking, it's their 'starting' positions. I'll give you an example:

 

A CM/D and a CM/S in a 442 formation are the midfield next to each other. They have the same 'starting position', but the Defend Duty player will defend deeper when in the defensive phase. The formation screen shows that by shifting him back just a little.

Obviously, given their duties, the Defend Duty player won't make forward runs and remain 'behind' play, while the Support Duty player will support play and get forward when the time is right. Attack Duty players (for the most part) bomb forward and are very aggressive in making forward runs.

 

[psucolonel]

Ok thank you.  This makes sense.  So basically duties and player instruction dictates where a player ends up after this initial starting position?