The space between centre-back and full-back

Watch the opening minutes of any match where one team sets up in a back four against a front three. The full-back has a decision to make: stay compact with the centre-back or push higher to press the winger. That decision creates the space.

Against a 4-3-3, the wide forward pins the full-back. If the full-back stays narrow to protect the centre, the winger receives on the turn and drives inside. If the full-back presses high, the space opens between him and the centre-back for the opposite winger or the midfielder running from deep. The passing lane disappears when the two defenders stay close. Otherwise, it is there the whole match.

In recent Serie A matches, the best teams show this in the first ten minutes. Watch where the full-back stands when the ball is on the opposite side. If he is five metres from his centre-back, the shape is sound. If he is higher, the centre-back covers alone and the midfielder has to drop.

The full-back position tells you more than the possession stat.

Question: In the next match you watch, check the distance between the full-back and centre-back in the first ten minutes. What does that distance tell you about the opponent's attacking shape?