Soccer Multiple Layers of Defenders

As attackers move the ball around the field, defenders should be constantly shifting to maintain good defensive coverage and the players farthest from the ball should "sag" back so they are in position to stop an attack on goal (this shifting & sagging compacts the defense provides additional "depth" & concentration of defenders between the ball & the goal). This creates "multiple layers" of defenders in a position to stop an attack on goal. Depth on defense means having several defenders (ideally, multiple layers of defenders) spaced between the ball and the goal who are in a position to "recover" in time to stop an attack on their goal. This and First Defender / Second Defender are the most important defensive concepts. Depth is the opposite of a "flat" defense. See Support.