Most race events use a traditional bracket system, where the losing car and driver are eliminated from the event while the winner advances to the next round, until a champion is crowned. Events can range from 16 to over 100 car brackets. Drivers are typically seeded by elapsed times in qualifying. In bracket racing without a breakout (such as NHRA Competition Eliminator), pairings are based on times compared to their index (faster than index for class is better). In bracket racing with a breakout (Stock, Super Stock, but also the NHRA’s Super classes), the closest to the index is favorable.
A popular alternative to the standard eliminations format is the Chicago Style format (also called the Three Round format in Australia), named for the US 30 Dragstrip in suburban Gary, Indiana where a midweek meet featured this format. All entered cars participate in one qualifying round, and then are paired for the elimination round. The two fastest times among winners from this round participate in the championship round. Depending on the organisation, the next two fastest times may play for third, then fifth, and so forth, in consolation rounds. Currently, an IHRA 400 Thunder championship race in Australia uses the format.