Pull on your boots. Grab your hat. Saddle up. The Round of 12 in the NASCAR playoffs begins Sunday at Texas Motor Speedway. The 1.5-mile track in Fort Worth hosts its 19th postseason event for the Cup Series (2:30 p.m. CDT, USA Network) with 12 drivers within 36 points of each other. That includes the "hometown" entrant, Chris Buescher of…