Beginning with the 1999 NASCAR Winston Cup Series, NBC began its foray into NASCAR. NASCAR on NBC, along with NASCAR on Fox and NASCAR on TNT, obtained the broadcast rights of the top two series – the NASCAR Cup Series and NASCAR Xfinity Series – in a six-year deal, beginning in 2001. NBC televised the second half of the season and alternated coverage of the Daytona 500 with Fox. In December 2005, NBC announced that it would not renew its agreement with NASCAR. In 2001, NBC obtained the broadcast rights to horse racing's Triple Crown of Thoroughbred Racing in a five-year deal.