'TDN Rising Star' Prime Factor (Quality Road), a blowout maiden winner sprinting on debut at Gulfstream Dec. 12, heads straight to the big leagues in Saturday's GIII Holy Bull S. The WinStar Farm and CHC Inc. colorbearer, a $900,000 Keeneland September yearling, worked a bullet five furlongs in :59 4/5 (1/13) at Todd Pletcher's Palm Beach Downs base Jan. 23 in preparation of his two-turn debut. Prime Factor is out of a half-sister to fellow 'Rising Stars' Speightster (Speightstown) and West Coast Swing (Gone West) as well as SW Paiota...