Although he worked Friday in a conventional bit at Churchill Downs, Vyjack has done all his training locally in a hackamore, a head piece that does not contain a bit but has a special type of noseband that helps a rider exert a little more control over a horse. [DERBY WATCH: Top 20 Kentucky Derby contenders with odds and video] “We started using a hackamore after his first race this year,” said trainer Rudy Rodriguez, who was also aboard Vyjack during Friday’s work. “He became a little more aggressive than we wanted him to be in the morning and felt if he was going to compete at a high level, we needed to teach him not to go crazy the whole way around each day. A lot of horses start like that, they go too fast and begin developing physical problems. We tried a lot of different bridles and I think this was our last option. The hackamore fit him perfect and he’s galloped like a pony in it ever since the first morning we tried it.” Rodriguez said a hackamore can be a bit too harsh to use during workouts. “If you don’t know how to take a hold of it just right, it can cut off a horse’s airways and could be a problem during a work,” Rodriguez explained.