A false nine tears a pure zonal midfield apart, and always has

Open-play zonal defending falls over the moment somebody refuses to occupy the zone they are supposed to occupy.

Set-piece zonal marking gets all the argument. Open-play zonal defending gets almost none, and it is the more interesting problem, because in open play the zones move and the players inside them are allowed to do whatever they like.

A zonal midfield works on responsibility areas. You are accountable for a patch of grass, roughly ten by fifteen metres, and anyone who enters it is yours until they leave. Nobody follows anyone. The shape stays intact and passes get intercepted because there is always a body in the passing lane. Neat, tidy, defensible against most opponents.

Then the centre-forward drops. Not into the midfield line, which would be simple, but into the seam between the centre-backs and the midfield, in the zone that belongs to nobody because it is the boundary between two responsibility areas. The centre-back's zone stops there. The midfielder's zone starts a couple of yards behind him. The forward stands in the gap with his back to goal and waits.

Now somebody has to break the system. If the centre-back steps, the back line has a hole and a winger is already running into it. If the midfielder drops, the space in front of him opens and the opposition eight arrives late into it, unmarked, in shooting range. If neither goes, the forward turns and runs at a back four with the whole midfield behind him.

Every decent side has an answer, and the answer is almost always a hybrid. You keep zonal principles for shape and you add man-oriented triggers for specific opponents: whoever the dropping forward is, one nominated midfielder goes with him, everywhere, and the rest shuffle to cover his patch. That works. It also requires a midfielder with the discipline to follow someone into a bad position and trust the cover, which is a genuinely difficult psychological ask.

My view is that pure systems of any kind are a coaching-badge fiction. Pure man-marking loses the shape. Pure zonal loses the seams. Every side that actually wins things plays some ugly, unnamed mixture that is really a set of if-then rules built for that week's opponent, and the tidy diagrams we all draw afterwards are a story we tell about what happened.

The question worth asking about any defensive scheme is not whether it is zonal. It is what happens in the two yards between one player's responsibility and the next player's. That is where the goals live.