When a race is red-flagged, teams are allowed to change tyres in the pit lane while the cars are stopped, and that change counts as the mandatory pit stop. It costs nothing.
A driver who has already stopped has spent nearly 22 seconds doing it. A driver who has not just got the same thing free.
That is the single most consequential rule in this article, it has decided real races, and the sport's own chief executive has said it needs fixing. It is still there.
What is a red flag in F1?
A red flag stops the session immediately. Race control uses one when an incident is too large to manage any other way: a major accident, a barrier needing repair, debris that cannot be cleared under a safety car, or weather that has become unsafe.
Drivers slow, follow marshal instructions and return to the pit lane at a controlled speed. The race clock keeps running. The cars sit stationary while the problem is dealt with.
