When defending in a 4-4-2 formation it is essential to keep a compact shape between the midfield and the back four. This means having a small distance between the midfield and the backline.
The tighter the distance, the less chance a team has of getting in that advantageous position of being on the ball, behind the midfield, and running at the back four.
Good communication and a desire to defend is required when creating this compact block of eight.
The opposition cannot harm you when they are playing in front of you.
The centre backs are expected to deal with any long balls by winning their headers and the compact shape should lead to a midfielder picking up the second ball, or at least competing for it.
If the opposition are good enough to feed the forward to his feet, the compactness of this shape should lead to the defender pressuring the ball from behind and the midfielder pressuring the forward from the front, just waiting for the forward to mis-control the ball. This pressure should lead to a challenge or a turnover in possession.
When a ball does find its way through to the opposing forward’s feet it is a good tester to see if you have the distances right between defence and midfield. Ideally, by the time the ball reaches the forward, a midfielder should be within tackling range after the forward's first touch to control the ball. A bad touch should provide an opportunity to regain possession.
If the opposition’s back four are passing the ball about, the front two should apply pressure on them. This should, eventually, force the opposition to pass it into the midfield or long to the front two, where the compactness of the team will prove it very difficult for them to find a way through.