The Chase for the Sprint Cup, originally known as "The Chase for the Championship" during its creation, and then "The Chase for the Nextel Cup" is the championship system used in NASCAR's top division, the Sprint Cup Series, akin to the postseason in American professional sports leagues. The Chase was announced on January 21, 2004, and first used during the 2004 Nextel Cup season. The format used from 2004 to 2006 was modified slightly starting with the 2007 season. Beginning with the 2008 Sprint Cup Series, the Chase became known by its new name as a result of the merger of Nextel Communications with Sprint Corporation. A major change to the qualifying criteria was instituted in 2011, along with a major change to the points system. Even more radical changes to the qualifying criteria, and to the format of the Chase itself, were announced for the upcoming 2014 Sprint Cup Series. As of 2014, the 10-race Chase involves 16 drivers chosen primarily on wins during the "regular season"; if fewer than 16 drivers win races during the regular season, the remaining field is filled on the basis of regular season points.