The defensive line is drawn by whoever turns slowest

Coaches talk about stepping up as a collective decision, when the line really sits where the least mobile defender can still survive.

Ask a coach where his defensive line is and he will give you a number in metres from his own goal. Ask the centre backs and you get a different answer, because the line is not really chosen. It settles. It settles at the depth where the slowest man in the back four believes he can turn and run with whoever is behind him.

That is a physical constant, not a tactical instruction. A defender who needs three strides and a wide arc to reverse his direction has to buy that space in advance by standing deeper. A defender who can pivot on one foot and be at pace within two steps can afford to stand twelve yards higher, and the whole team gets compressed as a result, and suddenly the midfield press works because there is no gap to play into.

Which means signing a quick centre back is not a defensive purchase. It is an attacking one. Every yard the line moves forward is a yard the entire block moves forward, and the difference between defending on the halfway line and defending ten yards deeper is the difference between winning the ball in the opponent's half and winning it in your own. Same players everywhere else. Completely different match.

I would go further and say the turning ability matters more than straight-line speed, and we consistently scout the wrong one. A defender with a fast forty and a slow turn will be beaten repeatedly by a striker who simply spins him, because the race never happens from a standing start in a straight line. It happens with the defender facing the wrong way.

The trap itself, the coordinated step forward, is a separate skill and honestly a slightly overrated one now. It is rehearsed, it looks glorious when it works, and it gets adjudicated afterwards by margins no player can perceive. Building a defensive identity around a mechanism decided on frames is a strange thing to do, and I suspect the fashion for it is partly nostalgia.

Compression is the real prize. Not the caught striker, not the raised arms. The line sits higher, the midfield sits higher, the forwards have thirty metres less ground to cover in the press, and the opponent's centre backs get four seconds on the ball instead of eight.

Buy the turn. The step forward is decoration.