Charles Town has a reputation as fertile ground for apprentice riders. Trainers, eager for any advantage they can get in sprint races as short as 4 1/2 furlongs, are willing to give live mounts to inexperienced jockeys in exchange for getting five to seven pounds off their horses. Many of those young jockeys have succeeded, most prominently Jose Montano, who won an Eclipse Award as leading apprentice rider in 2012. The newest apprentice at Charles Town to quickly make an impact is Jarred…