Chase for the Championship

In college basketball it’s called March Madness. In pro football, it’s the Playoffs, and in baseball, the World Series. In NASCAR, it’s the Chase for the Championship.
 
Before 2004, championships in NASCAR were won by the driver with the most points at the end of the season.  It changed as a result of Matt Kenseth winning the championship in 2003 even though he had won only one race. As with other years as well, Matt ran away with the points early, giving other drivers no chance to catch up, something which hurt viewership.
 
Taking its formula from the USAR Pro Cup Series model, Nextel changed the points system and created the Chase for the Championship, setting an even field in which the top twelve drivers of the regular season can compete.  Even though the formula has been adjusted over the past three years, in 2007 each driver that made the Chase will received 5,000 points, plus 10 additional points for each race he won during the first 26 races. Race layouts remained the same and points were scored the same way in the final 10 races. The leader in points after the 36th race was declared the NEXTEL Cup champion.
 
Usually multiple drivers still have a shot at winning the Championship right up until the very last lap. This has added a lot of excitement to the end of the NASCAR season.
 
In order to encourage competition among drivers who missed The Chase, NASCAR began awarding a one million dollar bonus to the driver that finished thirteenth in the points. That driver also gets invited to the end of year banquet to accept the award.

How Stuff Works spells out how the NASCAR Point system works