Qualifying and resetting
The playoff field is drawn from the regular season, with race winners taking priority and the remaining places going on points. Once the field is set, the points are reset to a common baseline with small seeding bonuses attached, which means a season-long advantage is compressed into a few points rather than carried whole.
This is the format's most debated feature. It guarantees a close finish and it produces drama in every round, at the cost of the older idea that a championship should measure a full year of performance.
Elimination rounds
The playoff runs in rounds of a few races each, and each round eliminates the lowest-scoring contenders. Winning any race in a round advances a driver automatically, which changes behaviour: a driver on the cut line will gamble on strategy or fuel because a win removes all uncertainty, while a comfortable driver protects position.
The mix of track types inside each round matters as much as the maths. A round containing a superspeedway introduces genuine randomness, because a crash there can take out several contenders through no fault of their own.
The finale
The last race is a straight contest between the remaining contenders: the highest finisher among them wins the championship, whatever anyone else does. It is the clearest race of the season to follow, because the story reduces to a handful of cars and their relative positions.
It also means a champion may not have led the year on merit. Supporters argue that a title race should be watchable to the last lap; critics argue a season should not turn on one afternoon. Both readings are fair, and the sport has moved between them more than once.