Judge a ground by how fast it empties

Arrival is a trickle spread over two hours; departure is fifty thousand people wanting the same exit in four minutes.

Arrival is a trickle. Departure is a flood. Those two sentences explain more about stadium design than any seating plan.

People come to a match across a long window. They arrive by different routes, at different times, some three hours early for a drink, some at the last minute from an office. The building never has to handle everyone at once. Then the final whistle blows and, within about four minutes, a very large fraction of the crowd stands up and heads for a staircase.

Egress is the constraint that shapes everything, and it is enforced by regulation rather than left to taste. Every stand has a calculated time in which it must be cleared to a place of safety, and the seat count that a ground is allowed to sell is derived backwards from stair widths, exit gate widths and the flow rates those can carry. Capacity is not a decision about how many chairs fit. It is a consequence of how quickly the building can be emptied.

Which is why so many otherwise excellent grounds have an unpleasant twenty minutes at the end. The stairs pass certification. Certification is about safety, not comfort, and a stand that empties inside its legal time can still feel like a badly organised crush, because the bottleneck usually is not the stair at all. It is what happens outside: one bridge, one underpass, one station with three ticket gates.

That is the part clubs cannot control and are judged on anyway, and the honest ones plan for it. Staggered exits by stand. Fan zones designed to hold people voluntarily after the whistle so the flow spreads over forty minutes instead of five. Late-running transport agreed in advance rather than negotiated after complaints.

The versions that fail are the ones that treat the crowd as a problem to be pushed out of the door as quickly as possible. Push fifty thousand people at a bridge that carries eight thousand an hour and you have simply moved the queue to a place you are not responsible for.

I have been in two brand new stadiums where getting out took longer than the second half was long. Both were praised for their concourses.

A ground is not finished at the turnstile. It is finished at the station.