The term "Balance of Performance" originates from the creation of Group GT3 in 2005 for the 2006 racing season. The concept drew on lessons learned from the homologation special phenomenon that had distorted competition in earlier GT classes, where manufacturers produced short runs of road-legal cars primarily to qualify a race variant for competition. BoP provided an alternative framework: allow a wider variety of production-based cars to compete together, then equilise their performance through measurement and adjustment rather than through prescriptive technical regulations.
BoP is determined through testing and data analysis, with car performance assessed across previous races and, in some series, even between sessions within the same race weekend. For new-to-class cars without a race history, organisers may use wind tunnel testing and dynamometer evaluation alongside track testing.
For GT3 cars in the SRO Motorsports Group ecosystem, two dedicated BoP tests are held each year at Circuit Paul Ricard. Cars are driven by drivers who already compete in them, and each car carries an organiser-supplied telemetry device to record performance data. Results from testing and races are used to adjust power output, minimum weight, and aerodynamic parameters for each individual model. These adjustments can be made at any point during the season in response to emerging performance trends.
Different sanctioning bodies apply different BoP methodologies. The ACO and IMSA have historically calculated BoP differently for LM GTE cars even when the same cars appeared in both championships. In the TCR touring car category, an additional mechanism called compensation weight provides a further layer of equalisation on top of the base BoP.
The Japanese Super GT series applies a different approach called success ballast, which penalises only vehicle weight based on results, leaving other performance parameters untouched. In the LMP1 prototype class of the FIA World Endurance Championship, a related concept called Equivalence of Technology was used to balance hybrid and non-hybrid cars — a more complex variant of the BoP principle applied to prototype machinery. Since 2025, the British Touring Car Championship has used a TTB system that adjusts only turbo boost pressure to achieve comparable equalisation.
BoP mechanisms are periodically subject to controversy over sandbagging, where a team or manufacturer deliberately underperforms during testing or certain races to receive a more favourable BoP adjustment. The Ford GT run by Chip Ganassi Racing attracted such accusations from rival teams during the 2016 FIA World Endurance Championship season, including claims of sandbagging ahead of the 2016 24 Hours of Le Mans qualifying session. To deter sandbagging, IMSA introduced a rule mandating a five-minute stop-and-go penalty during the 24 Hours of Daytona for any car found to have sandbagged during the pre-race Roar Before the 24 test session.
Several major sim racing titles implement BoP as part of their competitive multiplayer infrastructure. Gran Turismo Sport, Gran Turismo 7, RaceRoom, and Assetto Corsa Competizione all include simulated BoP adjustments for eligible cars, allowing mixed-manufacturer competitive racing within defined performance envelopes. This reflects the system's influence beyond professional motorsport and into the wider driving simulation community.
BoP has become a defining feature of GT racing from GT3 through LM GTE and GT4, enabling series to attract a broad roster of manufacturers without requiring identical machinery. It shifts competitive focus partly from pure engineering resources toward driver skill, team strategy, and tyre management, while creating the commercial appeal of varied grids populated by recognisable production-car silhouettes. Its widespread adoption across global GT and touring car series since 2006 has fundamentally shaped the structure of contemporary sports car racing.