An overlap is a decoy first and a passing option second

The run outside the winger is judged by whether it receives the ball, which is the least useful thing it does.

Say a full back makes twelve overlapping runs in a match and gets the ball twice. The commentary calls that wasted energy. The coach who designed it calls it ten successful repetitions, and the coach is right.

An overlap works on the defender, not on the ball. A full back defending a winger is solving a two variable problem, inside or outside, and he solves it by setting his feet and body angle to shut one and dare the other. The overlapping runner destroys that. The instant a second attacker crosses into his outside shoulder the defender has to make a decision he cannot make alone, and either he stays and concedes the run or he opens his hips towards the touchline and concedes the inside cut that the winger actually wanted.

Which is why the best overlaps end with nothing happening to the runner at all. He goes past, unused, and the goal is scored by the man who now has a defender facing the wrong way. Count the assist and it belongs to somebody else. Count the mechanism and it belongs to the run.

This is also why the underlap became popular and why I think it is slightly overrated as a replacement rather than an addition. An underlapping run threatens the space behind the centre back and forces the defender to worry about a different door, but it does not open the touchline, so a winger who likes to go outside gets nothing from it. Sides that have swapped entirely to underlaps have made their wide play more central and easier to compress, which is fine against a low block and poor against a team that presses wide.

The measurement problem sits underneath all of this. Every public statistic about wide play counts events involving the ball, and the overlap is a run whose value is that it does not involve the ball. So the metric penalises the player doing the work and credits the player who benefits, which then feeds into recruitment, which is how you end up buying the winger and wondering where the goals went.

Watch the defender's hips. That is the whole argument, and it takes about four seconds to verify.