At a standard BTCC race weekend, qualifying on Saturday determines the starting grid for Race 1 on Sunday. Race 2 uses the finishing order of Race 1 as its grid. For Race 3, a reverse grid applies: a portion of the Race 2 finishing order is inverted to establish the starting positions.
The specific mechanism for determining the inversion point has changed over the championship's history. Before 2006, the driver who finished in tenth place in Race 2 automatically started from pole position for Race 3. The drivers in positions one through nine from Race 2 then started Race 3 in reverse order — ninth place on the Race 2 result took second on the Race 3 grid, eighth took third, and so on — with drivers finishing eleventh and beyond retaining their Race 2 order from eleventh place onward.
From 2006, the system was revised. A draw takes place to determine which finishing position from Race 2 will take pole position for Race 3. A ball is drawn — typically by a celebrity or VIP, conducted live on television — from a range corresponding to positions six through twelve. Whichever number is drawn, the driver finishing in that position in Race 2 starts Race 3 from pole. Those who finished ahead of that position in Race 2 line up in reverse order behind them, while those finishing from one position behind the drawn number onward retain their Race 2 order. A specific variant introduced for 2014 gave the driver who finished tenth in Race 2 the authority to draw the ball rather than a celebrity guest.
The reverse-grid format has polarised opinion throughout its use in the BTCC. Supporters argue that it maximises on-track action, creates meaningful race-long battles for positions, and gives backmarkers and midfield competitors the chance to lead a race in front of the crowd and television audience. For independent teams and privateers who are unlikely to challenge manufacturer-backed front-runners in open competition, the reverse grid provides race-winning opportunities that would otherwise be unavailable.
Critics, including some drivers and purists, argue that the format undermines the competitive integrity of racing by mechanically favouring drivers who have performed poorly. The inversion of merit — placing the slower qualifier or finisher on pole — runs counter to the traditional sporting principle that the fastest car and driver should start at the front.
The pre-2006 fixed tenth-place rule created an additional problem: it generated direct incentives for deliberate slow driving. Some drivers attempted to finish in exactly tenth place during Race 2 rather than pushing for the highest possible position, because a tenth-place finish guaranteed pole for Race 3. This behaviour, sometimes called strategic slowing, led to drivers braking heavily on the approach to the finish line with cars immediately behind forced into evasive manoeuvres, creating safety concerns as well as sporting distortion. Fabrizio Giovanardi drew specific attention for successfully managing this calculation on more than one occasion, drawing the ball number corresponding to tenth while he was himself finishing in that position. These factors were the primary motivation for the rule change introduced for the 2006 season, replacing the fixed tenth-place rule with a draw to make the outcome unpredictable in advance.
The reverse grid concept in the BTCC predates the widespread discussion of similar mechanisms in other series, including Formula 1, where reverse-grid sprint races were debated but not adopted during the 2020s. The BTCC's long experience with the format has provided evidence both of its effectiveness in producing varied race results and of the complications it introduces when the specific inversion point is known in advance. The draw-based system introduced in 2006 addressed the latter concern while retaining the fundamental entertainment and access benefits of inverting a portion of the grid.