The overlap works because nobody takes it

An overlapping run is most valuable as a threat that pulls a defender wide, not as a pass that actually gets played.

A full back sprints past his winger, screams for it, and the winger cuts inside and shoots. The full back throws his arms up. The crowd groans. And the move was completely successful, because the defender who followed the overlap is the reason the shooting lane opened.

This is the thing about decoy runs that pundits struggle with. The run is not a request. It is a question posed to a defender, and the defender has to answer it in a fraction of a second with incomplete information. If he follows, the inside opens. If he stays, the pass outside is on and the cross comes in unopposed. Either answer is a loss for him, which is why the run is worth making even when the ball never goes there.

You can see the mechanism most clearly in how sides defend it, which is by having the winger's own defender track the overlap while the full back's defender stays inside. That requires a hand-off executed at speed with an opponent between you, and it is one of the harder pieces of defensive coordination in the game. It also requires the two defenders to have agreed in advance, which is why overlaps hurt newly assembled defences far more than settled ones.

The underlap has become fashionable partly because it poses a harder question. A run inside the winger, into the channel between full back and centre back, is on the blind side of both, and neither is confident whose problem it is. I think it is a better run in most situations and I would like to see it more often from actual full backs rather than only from midfielders drifting wide.

What annoys me is the statistical treatment. Runs that do not receive the ball are invisible in essentially every public dataset, so a full back whose value is largely in the running he does for other people looks ordinary on paper and gets sold. Clubs with tracking data know better. The public conversation does not, and it is still the conversation that sets a player's price.

Count the runs, not the passes. The pass is just the occasional confirmation that the run was real.