Every trainer deals with difficult horses, and sometimes they work out and sometimes they don't. There was a time when Graham Motion didn't know whether Mean Mary (Scat Daddy) would fulfill her potential. Owned and bred by Alex Campbell Jr., she was that tough. "You had to have your best rider on her," Motion said. "You had to have her on the pony or she'd pull some antics going to the track. Nothing that was unmanageable, but something you always had to be ready for. She was just very tough."...