Mario Pino, 15th on the all-time list of leading riders with 6,216 victories, will begin riding at Philadelphia Park on Monday. Pino, fourth at the recently concluded meet at Presque Isle Downs, will be represented by Craig Donnelly, who spent 37 years as a public handicapper for the Philadelphia Inquirer. . . . For the second straight year, Turfway Park will conduct an exhibition race for graduates of the North American Riding Academy, the Lexington, Ky., school founded and operated by Hall of Fame jockey Chris McCarron. The 5 1/2-furlong race will be run Friday at about 6:20 p.m. Eastern, before the 10-race evening card starts. Six graduates will compete: Matthew Straight, Ben Creed, Kristina McManigell, Katherine Peddicord, Ryan Pacheco, and Claire Scholly.