The $750,000 Pennsylvania Derby (gr. II) Sept. 6 may draw as many as 12 to 13 starters, in what promises to be a competitive race. Although the absence of Smarty Jones will be felt by the large holiday crowd, the 1 1/8-mile race is expected to draw some of the top 3-year-olds in the country.Those considered definite are Wood Memorial (gr. I) winner Tapit, who has not run since the Kentucky Derby (gr. I); Pollard's Vision, winner of the Illinois Derby (gr. II) and Leonard Richards Stakes (gr. III); Niigon, winner of the Queen's Plate (Can-I); My Snookie's Boy, runner-up in the Haskell Invitational (gr. I); Master David, second in the Wood Memorial; Pies Prospect, third in the Haskell; Royal Assault, winner of the Sir Barton Stakes and third in the Belmont Stakes (gr. I); Swingforthefences, winner of the Iowa Derby; Separato, explosive winner of the President's Cup at Philly Park; Song of the Sword, second in the Illinois Derby; Love of Money, winner of two of three career starts; and Wimplestiltskin, stakes-placed in California, but beaten off in the Haskell.Questionable are Mustanfar, DQ winner of the Lexington Stakes (gr. IIIT); and Reggie For Three; a Saratoga allowance winner going nine furlongs in his last start.With Jerry Bailey out with a broken wrist, Eibar Coa will substitute aboard Master David for trainer Bobby Frankel.Nick Zito, who ran one-two in the Travers Stakes (gr. I) last weekend, will try to duplicate that feat when he saddles Pies Prospect, with Chuck Lopez up, and Royal Assault, to be ridden by Pat Day. Separato is an intriguing colt, having come from 15 lengths back in the President's Cup and making a spectacular move around horses to draw off to a five-length victory in the quick time of 1:41 4/5 for the mile and 70 yards. He is trained by Tim Ritchey, who also has undefeated Afleet Alex, winner of the Hopeful Stakes (gr. I) on Aug. 21.