PPDA cannot tell a press from a defence that has given up

The most quoted pressing metric in football is a ratio whose denominator is controlled entirely by the other team.

Imagine two sides with an identical pressing number. One suffocates the opposition into rushed passes and turnovers in the final third. The other is so passive that the opponent's goalkeeper simply hits it long every time, which produces almost no opposition passes at all. The metric cannot separate them, and it is quoted every week as though it can.

Passes allowed per defensive action counts what the opposition does with the ball in their own territory and divides it by your attempts to stop them. That is a reasonable idea. The trouble is that both halves of the ratio are contaminated. A team that presses ferociously and wins the ball at once generates very few opposition passes, which flatters it, but it also generates very few defensive actions, because it did not need many. A team that presses badly and gets played through generates plenty of both. The arithmetic does not have a way of telling you which happened.

The long ball is the clearest break. Any opponent who declines to build from the back removes the denominator entirely. Their goalkeeper kicks it, there is no sequence of passes to count, and the pressing side's number moves without any change in behaviour. So a team can improve its pressing metric by playing an opponent who is frightened of it, which is exactly backwards from what a measurement should do.

There is a location problem too. Defensive actions in the opposition half are treated identically regardless of whether they occur near the halfway line or twelve yards from goal, and those are not the same event. One is a containment. The other is a scoring chance.

What I would use instead is unglamorous and available. Measure the time between the opponent gaining possession and your first defensive contact, and measure where the ball ended up ten seconds later. Speed and territory. Those two describe a press in a way a ratio never will, and neither can be gamed by an opponent who refuses to play.

The reason PPDA persists is that it is one number, and one number fits in a graphic. That is not a good enough reason to keep explaining a season with it.