The NASCAR Sprint Cup Series (often shortened to Sprint Cup or the Cup Series) is the top racing series of the National Association for Stock Car Auto Racing (NASCAR). The series is named after its current sponsor, Sprint Nextel, and has been known by other names in the past. It was originally known as the Strictly Stock Series (1949) and shortly after became the Grand National Series (1950-1970). While leasing its naming rights to R. J. Reynolds Tobacco Company, it was known as the Winston Cup Series (1971-2003). A similar deal was made with NEXTEL in 2003, becoming the NEXTEL Cup Series (2004-2007) and it became the Sprint Cup after Sprint acquired NEXTEL in 2005. The name "Sprint" refers to the corporation of the same name; sprint car racing is a seperate racing discipline.
The drivers' champion is determined by a point system where points are given according to finishing placement and laps led. The season is divided into two segments. After the first 26 races, the 10 highest ranked drivers, plus the two drivers with the most race wins who are ranked from 11th through to 20th in points, are seeded based on their total number of wins and compete in the last ten races with the difference in points greatly minimized. This is called the Chase for the Championship.
The series holds strong roots in the Southeastern United States with half of its 36-race season in that region. The Daytona 500, its most prestigious race, had a television audience in the U.S. of about 16 million viewers in 2009. Previously, races have been held in Canada, and exhibition races were held in Japan and Australia.
Sprint Cup Series cars are unique in automobile racing. The engines are powerful enough to reach speeds of over 200 mph (320 km/h), but heavy weight - coupled with a relatively simple aerodynamic package - makes for poor handling. Their bodies and chassis are strictly regulated to ensure parity, and electronics are spartan in nature.