Depth being - formation, shape, the lines i.e. 4-2-3-1 = 4 lines of defense, 4 lines of attack.
The specific principles of attack that we will refer to, then, are Penetration, Width, Support, and Mobility. This is best remembered in the maxim “if you can’t go forward, go wide; if you can’t go wide, go back; if you can’t go back, then move until you can go forward again”. The corresponding defensive principles, then, are Pressure/Delay (to prevent penetration), Cover (to mark the supporting attackers), Balance (to ensure that width doesn’t create central space through which to penetrate) and Consolidation/Concentration (to ensure that mobility doesn’t destroy the shape of the defence)
For example....
Penetration in Attack would be linked closely with tempo and passing. The quicker the tempo. The more direct more the passing. The more slower the tempo. The less direct, more patient the passing. This is a general rule, of course a team can play short passing but a quicker tempo, mix things up but generally.....
PENETRATION: Slow tempo = more side to side, back passing = short passing.
SUPPORT: more support in numbers, players contributing to more phases of play i.e. CB's only responsible for the defensive and transitional phases - ball playing CB's, FB's and DM's for the defensive, transitional and attacking phases - deep lying playmakers..
WIDTH: more width/side to side movement, stretching the oppositions defense/shape.
MOBILITY: more mobility/more mobile players capable clever off the ball movement.
A team who plays more direct, generally...
PENETRATION: Quicker tempo = less side to side, more vertical/up and down = direct passing.
SUPPORT: less support in numbers, players contributing to less phases of play - i.e. CB's responsible for the defensive phase only, FB's and DM's the defensive and transitional phases.
WIDTH: lees width/more narrow/less side to side movement, stretching the oppositions defense/shape - rather cutting straight thur it.
MOBILITY: less mobility/the importance of having mobile players capable clever off the ball movement is far, far less.... 2-3 players who have lots of pace, direct running/dribbling ability is a lot more important.