In sports car racing, balance of performance (BoP) is a regulation and mechanism that maintains parity between competing vehicles by adjusting the limits and parameters of a vehicle such as horsepower, weight, engine management, and aerodynamics to prevent a single manufacturer from becoming dominant in a racing class or series.
The origin of the term "balance of performance" dates back to the creation of Group GT3 in 2005 for the 2006 racing season, using experience learned from the homologation special phenomenon in previous GT classes.
[1] The system was later adopted for other production-based racing categories such as Group GT4, LM GTE and TCR Touring Cars.
Although one-make, open-wheel and prototype car racing typically do not use a balance of performance regulation, a similar system was devised for the LMP1 class in the FIA World Endurance Championship called equivalence of technology (abbreviated EoT), that allows for parity between hybrid and non-hybrid cars in the class.
[2] DPi cars in the IMSA WeatherTech SportsCar Championship are also subject to balance of performance regulations.