Compactness is measured vertically and defended horizontally

Coaches obsess over the distance between defence and midfield and lose more goals to the gaps that open sideways.

Twenty five metres. That is the number that gets quoted for the distance between the last line and the midfield line, and it is a reasonable target and it has become a fetish.

The vertical version of compactness is easy to see and easy to train. Push up, drop off together, keep the block shallow, deny the space between the lines. It works. It is also the half of the problem that opponents solved a long time ago, because a compact block that is compact only up and down can be pulled apart across the pitch by any team willing to switch the ball quickly.

Watch how goals against a well-drilled block actually happen. Rarely someone threading through the middle. Usually a long diagonal to the far side, the block shifting late, and a receiver in acres because the wide player on that side had tucked in to maintain the shape. The block was never broken. It was moved, and it moved slower than the ball.

Which is why the underrated quality in a defensive unit is not discipline but lateral speed, and specifically the speed of the second shift. The first shift across is easy; everyone reacts to a switch. It is the recovery when the ball comes straight back the other way that separates good blocks from famous ones, and it is a conditioning problem as much as a tactical one.

I would argue the current fashion makes this worse. Very narrow blocks that concede the touchline entirely are betting that the cross from wide is a low-value action, which is broadly true, and they are also guaranteeing their defenders repeated maximal lateral sprints for ninety minutes. Bet on the shot quality, pay in the legs.

There is a scoreline dimension too. A team defending a lead in the last ten minutes gets deeper and, because deeper means the pitch is wider relative to the block, its lateral distances get worse at exactly the moment its players are most tired. That is why so many late equalisers arrive from the flank after a switch.

If I were coaching it I would spend less time on the line between defence and midfield and much more on rehearsing the ball crossing the pitch twice.

Nobody films that drill. It does not look like anything. It is where the goals are.