Inverted full backs are cheap in build-up and expensive at the far post

Stepping a defender into midfield solves a problem in your own half and creates a different one on every cross you face.

The build-up case is settled and I have no argument with it. Bring the full back inside, get four passing angles instead of two, keep a centre back free, stop the opposition winger from pressing you along the touchline where the line does half the defending for him. It works. It has worked everywhere it has been tried by anyone competent.

Then the ball goes wide against you and the picture changes.

A cross into the box asks for four things: a man on the front post, a man on the striker, a man reading the cutback, and a man at the far post who is tall enough to head a ball that has travelled thirty-five metres. A conventional back four supplies those four bodies from the positions they were already standing in. A back four where one player has spent the last two minutes at the base of midfield supplies three of them, and the fourth arrives running backwards at the far post, having covered forty metres to get there, against an attacker who started facing the ball.

That is where the goals come from, and if you watch a season of a side that inverts on one flank you will see the same clip repeatedly. Cross from the far side, second phase, header back across, a scramble at the post the inverted player should be occupying.

Coaches know this. The fixes are all trades. You can invert only when the ball is on the same side, which halves the build-up benefit. You can invert a midfielder into the back line instead, which asks a midfielder to defend crosses, which is not obviously better. You can pick full backs who are six foot two and press-resistant in midfield, of whom there are perhaps twenty in Europe and all of them are expensive.

What annoys me is the way this gets presented as a free upgrade. It is a redistribution. You have taken risk out of your own build-up, where errors are visible and embarrassing, and moved it into your box, where goals look like accidents.

If your league crosses a lot, the trade may not be worth it. Nobody says that out loud because inverting looks modern and defending the far post looks like 1994.