Drifting competitions are judged based on line, angle, speed, amount of smoke, and show factor. Line involves taking the correct line, which is usually announced beforehand by judges. The show factor is based on multiple things, such as the amount of smoke, how close the car is to the wall or designated clipping point, and the crowd's reaction. Angle is the angle of a car in a drift, speed is the speed entering a turn, the speed through a turn, and the speed exiting the turn; faster is better.
The judging takes place on just a small part of the circuit, a few linking corners that provide good viewing, and opportunities for drifting. The rest of the circuit is irrelevant, except as it pertains to controlling the temperature of the tires and setting the car up for the first judged corner. In the tandem passes, the lead driver often feints his or her entry to the first corner to upset the chase driver, however in some European series, this practice is frowned upon by judges and considered foul play, resulting in deduction of points.
There are typically two sessions, a qualifying/practice session, and a final session. In the qualifying sessions, referred as Tansō (単走:solo run), drifters get individual passes in front of judges (who may or may not be the final judges) to try to make the final 16. This is often on the day preceding the final.
The finals are tandem passes, referred as Tsuisō. Drivers are paired off, and each heat comprises two passes, with each driver taking a turn to lead. The best of the 8 heats go to the next 4, to the next 2, to the final. The passes are judged as explained above, however there are some provisos such as:
* Overtaking the lead car under drift conditions is ok if you don't interrupt the lead car's drift.
* Overtaking the lead car under grip conditions automatically forfeits that pass.
* Spinning forfeits that pass, unless the other driver also spins.
* Increasing the lead under drift conditions helps to win that pass.
* Maintaining a close gap while chasing under drift conditions helps to win that pass.
Points are awarded for each pass, and usually one driver prevails. Sometimes the judges cannot agree, or cannot decide, or a crowd vocally disagrees with the judge's decision. In such cases more passes may be run until a winner is produced. Sometimes mechanical failure determines the battle's outcome, either during or preceding a heat. If a car cannot enter a tandem battle, the remaining entrant (who automatically advances) will give a solo demonstration pass. In the event of apparently close or tied runs, crowds often demonstrate their desire for another run with chants of 'one more time'.
There is some regional variation. For example in Australia, the chase car is judged on how accurately it emulates the drift of the lead car, as opposed to being judged on its own merit, this is only taken into consideration by the judges if the lead car is on the appropriate racing line. Other variations of the tansou/tsuiso and the tansou only method is the multi-car group judging, seen in the Drift Tengoku videos where the four car team is judged in groups.